Tag Archives: sidemount

The Bogaerthian Configuration

While backmount cave divers have mostly adopted the Hogarthian gear configuration, sidemount divers’ kit remain very individualistic. Without commercially available units, each sidemount diver built rigs based on different levels of knowledge and experience, different environmental challenges, different goals, and different ideas on how best to realize them.

In the past, many of the pioneering sidemount divers were dry cavers. As the result, they were comfortable building their own gear and this gear had to work in both the dry and wet sections of a cave.

When there were no readily available units, sidemount divers would either build a system from scratch or adapt an existing non-sidemount specific kit for their needs.

Even with the introduction of commercial systems (see the explosion of systems at DEMA 2009), many sidemount divers choose to modify and extend. This speaks heavily towards a strong individual streak in sidemount divers.

But it could also mean that no one has come up with a holistic gear configuration to meet most sidemount divers’ needs. While the Hogarthian backmount system is common these days, we must remember that it is a relatively recent innovation. Standardization in sidemount configuration is where backmount was 10-15 years ago.

After taking a sidemount course with Steve Bogaerts, I believe that his configuration does provide a holistic and standard system for sidemount divers.

Steve’s gear configuration shares a few key similarities to the Hogarthian backmount rig:

  1. 7′ long hose and shorter 22″-24″ hose, necklaced (“Basic” sidemount configuration).
  2. Single continuous 2″ webbing harness and a crotch strap.
  3. Minimalist approach to dive gear and set-up.

Hose routing
For sidemount divers diving at the basic level or in mixed teams of backmount and sidemount divers, the 7′ long hose and shorter 22″-24″ necklaced hose keeps OOG and gas-sharing protocols almost the same as in the Hogarthian gear. OOG diver receives the long hose, and the donating diver breaths from his short hose.

The difference for sidemount is that the donator may not be breathing the long hose when an OOG situation occurs. However, OOG situations are usually not without advance notice and the divers can plan accordingly. In addition, one breaths the long hose at the beginning and end of the dive, the most likely times of OOG situation.

Routing of the hoses on the sidemount diver is similar as well. The necklace is routed from the left tank, around the back of the neck, and delivers from the right side. The 7′ hose is partially tucked into the right tank’s bands, brought across the chest, around the back of the neck, and delivers from the right side.

When not in use, the 7′ hose is clipped to the right shoulder D-ring, with a breakaway connection. The boltsnap is close to the second stage to prevent dangling, but far enough to allow breathing from the stage without unclipping. If gas sharing may be required, then the long hose should be unclipped in preparation for easy handoff, unless it’s already in the diver’s mouth.

Each tank has an SPG attached to a 6″ HP gauge. The gauge is not tied back up to the first stage and remains flushed against the tank. The handwheels are positioned on the diver’s outside, and the valve stems face inward.

The first stages are faced up (towards the diver) and the SPGs rests on the tank. When the sidemount bungees are attached to the tanks, they rotate 45 degrees placing the handwheel in the armpit and the SPG between the tank and the diver’s body. This reduces entanglement and keeps the gear streamlined. To view gas, the diver flips the gauge up from the outside.

It is important to note that sidemount tanks should be considered your primary tanks, and set-up should not be confused with stage tanks and stage tank configurations.

After a couple of years of field trials, Steve’s harness is complete. He has dubbed it the “Razor Harness.”

Unlike the other sidemount harnesses currently available, the Razor is extremely minimalistic – A single 2″ webbing harness, a separate crotch strap, and two small stainless steel plates to give the harness shape. To hold the neck of the sidemount tanks, the Razor has one continuous bungee with a bolt snap on each end. Custom sized D-rings and two special tri-glide with an attached D-rings complete the harness.

Each shoulder contains a 1″ D-ring. The smaller D-ring minimizes movement of gear, and is the attachment point for the bungee and stages. In addition, they also function as a temporary work space, similar to backmount. When not using a helmet, I attach my backup lights to the shoulder D-rings as well.

The bungee is an in-water replaceable unit and is attached to the shoulder D-rings with a small bolt snap on each end. The custom length allows it to be as tight as possible, keeping the sidemount tanks secure to the body.

A primary cutting device is attached to the waist. Or Steve’s preference of the wrist.

Waist D-rings on the side of the body secure the bottom of the sidemount tanks. This is similar to carrying a stage in a backmount set-up. The significant difference is the Razor uses small 1/2″ D-rings. These very low profile D-rings reduce tank movement as it limits the distance between tank and diver. In addition, the bolt snap position on the sidemount tanks is different than a stage tank, and this further reduces tank movement.

Additional low profile D-rings are positioned between the hip and diver’s midpoint. These are used to secure butt light tanks in a horizontal position when they start to float. In reviewing other sidemount harnesses, the Razor is the only harness that has this feature.

Weights are threaded on the harness, generally on the back waist or on the back center piece. If more heads down trim is required, then weights can be placed on the shoulder straps where they exit the Razor’s Delta Shoulder Plate. The diver is weighted to be neutral in water, without tanks. Tanks are kept streamlined, and no weights are attached to tanks.

When the weights are back waist mounted, then triglides with small D-rings (Drop Attachment Points) help lock the weights in place. However, if position of weights makes DAPs location non ideal, then regular tri-glides may be used.

The Bogaerthian method mounts a detachable flat pouch to the DAPs. The pouch contains backup safety items as well as wetnotes. Backups include spare bungee, double ender, zipties, and a 2nd cutting device. This set-up is very streamlined, using 2 attachment points with double enders.

The small D-rings can be used as additional holds for spools or reels. I found these triglides with small D-rings very convenient as a temporary hand. Others use the DAPs to attach a canister light.

A butt mounted D-ring is available for additional space or longer term storage. Primary and exploration reels are best stored on this D-ring.

Personally, I chose to keep my contents in thigh pockets. This kept my backmount and sidemount configurations even more similar. However, there was a benefit to using the pouch, as it can be detached and brought in front of the diver. Then an item can be extracted and the pouch returned to the back position.

With thigh pockets, extracting items is by feel only. In addition, Steve notes that thigh pocket access becomes more difficult when carrying multiple stages. My short arms don’t help, but this is something I’ve worked on in BM configuration.

The Crotch strap serves multiple purposes. A smaller canister light is butt mounted on the crotch strap, and a larger canister via the DAPs. With the crotch strap on top of the canister, the canister is more securely held in place. The crotch strap also contains a scooter ring – for tow behind scooters. Lastly, the crotch strap keeps the harness snug and can provide a tie point for the BAT wings.


To reduce any chance of entanglement or line traps, tanks are streamlined. The only connection point is a small bolt snap attached to a line, held in place by a hose clamp. The line is as short as possible, only exposing enough to be able to cut in case of bolt snap failure.

The left tank has one hose retainer. When not in use, the regulator is tucked into the retainer. The retainer also serves as a back-up attachment point, in case of bolt snap failure.

The right tank has two hose retainers in the Basic configuration. The 7′ hose is tucked into the retainers, and they also serve as back-up attachment points.

Sidemount helmet

Sidemount diving seems like the last refuge of individualized gear. Whereas back mount cave divers have more or less adopted the hogarthian configuration, side mount set-ups are quite varied.

Even the newly off the shelf units such as the Golem Gear Armadillo and Dive Rite Nomad are constantly being modified or “improved” by their owners.

The first thing that most sidemount divers tackle is making a helmet. The base helmet is either a kayak helmet, prostate climbing helmet, artificial construction helmet, or skateboard helmet.

I chose a kayak helmet since they are designed for in water usage and I thought that the foam liner would be more secure than the suspension liner of other helmet styles. And if I didn’t like the foam, I could rip it out.

With price being a major consideration and preexisting holes being another, I selected the Pro-Tec Ace helmet. At $40 and free shipping, it wasn’t going to break the bank.

For my head size, I chose a Medium helmet. After the modifications and with the use of a hood, a Small would have been a better purchase.

sidemount diving helmet - dac

First step was to drill four holes on each side to mount the back-up lights (BUL). Since BULs mounted on the harness is not optimal (they are blocked and interfere with the side mount tanks), the helmet use have two BULs attached. Steve Bogaerts recommends mounting then so that there is no glare and the focus is 10 feet away.

After securing the BULs, the next step is creating a mount for the canister light head. This is accomplished by cutting the appropriate sized PVC tube or coupler and then drilling 4 more holes into the left side of the helmet. Placement is immediately above a BUL.

Once complete and tested on dry land, it was time to hit the water. Immediately, the helmet was too buoyant. The closed cell foam designed to protect against impact made me head light. To a surprising degree too. While this may be a nice feature for paddlers, it is obviously not good for divers.

To resolve this, I removed all the side and back foam. I kept the top foam to provide a place for my head to fit. Plus, this would insure that the height of the helmet was correct. Removing the top foam piece would have caused the helmet to ride too low.

With the foam removed, the helmet is neutral in fresh water with my UK SL4 BULs.

sidemount diving helmet - smb

How to Route Hoses on Sidemount Tanks

There’s a lot of variation on how people route their hoses on sidemount tanks. The basic method I learned from Steve Bogaerts for use with his Razor side mount harness is very simple, streamlined, and similar to the Hogarthian hose routing for backmount divers.

hose routing on sidemount tanks

Left Tank contains:

  1. Regulator on short hose and necklace – routed behind the neck, and into the mouth from the right side.
  2. SPG on 6″ hose – routed straight back to minimize entanglement.
  3. LP hose for drysuit. Note I used my drysuit for buoyancy and no add’l BCD. The hose in the picture is too long, and a 6″ hose would be ideal.

Right Tank contains:

  1. Regulator on the long hose – routed across the chest from the tank to the left shoulder, around the back of the neck, and into the mouth from the right side. One loop is captured in the tank bungee, similar to tucking excess hose under a canister light in Hogarthian configuration.
  2. SPG on 6″ hose – routed straight back to minimize entanglement.

Friday, April 17, 2009 – First cold water sidemount dives

Today, Kevin and I meet up with some friendly UTD divers visiting from SoCal. It’s their first trip to Pt. Lobos, and Kevin and I are eager to show them a good time.

By the time I arrive at 8:30am the parking lot is already full of divers. It’s one of those rare Fridays that a reservation is required – 5 divers were already turned away by the time I arrive. It’s also one of those Fridays that looks absolutely beautiful. The cove is glassy flat and viz, even top side, looks impressive.

Pt. Lobos

I attempt to take an iPhone photo to taunt my friends with, but the iPhone freezes. Hurray for the iPhone — the most overrate electronic device ever. Fortunately, Christian has his camera and is gracious enough to share (including the pictures below).

As we gear up, Kevin and I marvel at the amount of gear that keeps coming out of the SoCal divers’ van. The picture below is missing 3 add’l sets of doubles, Cubas, and bags and bags dive gear – all of it which went into one vehicle.

Van with tanks

Ted and Matt pull up and we trade dive plans. Our first dive with the LA crew is a kick dive to Hole in the Wall. Ted and Matt will scooter west of Lone Metridium and play in walls and valleys towards Marco’s Pinnacle. Although uncommon, that’s a spectacular dive.

In addition to taking our LA friends on a tour, I am eager to get in the water and try out the Razor harness. A couple weeks prior, I had used my wife’s old sewing machine and made a cover for my camelbak BCD. Today would be my first cold water sidemount dive.

First task is to stage the sidemount tanks in the water. Low tide can be dangerous and uncomfortable for doubles divers. However, carrying one tank at a time, navigating the slippery ramp proves to be far less challenging. +1 for sidemount.

As the backmount divers start getting ready, I jump in the water and start donning my gear. Since it’s the first dive, I want to the dive the rig as I did in Mexico. As the result, I am using the mini 1/2 inch D-rings. Definitely not that smartest decision, but I wanted a baseline for comparison.

Well, as you can imagine, I struggle to don the tanks. Clipping small bolt snaps onto even smaller D-rings proves to be chore with drygloves. I climb up onto the ramp and use the low tide to my advantage. The conditions couldn’t have been better, but it still takes me almost forever to get set-up. -1 sidemount (with warm water harness gear)

I finish donning just in time for the LA divers to get in the water and I help here and there. It’s mostly Kevin providing good direction on entry.

One of the big concerns I had before the dive was surface floatation. In Mexico, the Razor harness system is optimized for under water movement. Surface floatation does not exist. The good news is that my makeshift BCD keeps my head above water. The bad news is that every time I raise my left arm, the cuff dump burps and I’m at eye level. If sidemount becomes a cold water habit, I’ll have to plug up the cuff dump on those days. -1 for cuff dump.

We surface kit to above the worm patch, and it’s visible from the surface. After a minute to regroup the teams, we descend. I do a masterful job tangling my lightcord and twisting the canister so Kevin sorts me out at the bottom.

Under water, the sidemount tanks feel pretty good. Movement is easy and trim is spot on. With the LP77’s -6.8# buoyancy on each side of me, I’m physically locked into horizontal trim. In fact, when I rotate laterally, the tanks will snap my back to the horizontal plane. Personally, I like the ease of movement with lighter sidemount tanks, but overall it’s still a pleasure to dive. +1 for sidemount.

Dumping air from the camelbak BCD is more involved because of the cuff dump. When I raise my left arm to dump the BCD, the cuff dump would activate. As the result, I end up unrouting the BCD hose and dump from the right side of the body. Fortunately, I only had to do this a couple times during the early parts of dive. The BCD was sufficient to offset the extra weight of the gas in the beginning of the dive. In the later parts, I compensate buoyancy with my drysuit. -1 for cuff dump.

As we head away from the the worm patch, I immediately regret not taking my camera. Given the Razor harness’ maiden cold water voyage, I thought it best to leave my small point-n-shoot on shore. Visibilility is stunning, at least 50′. With the bright sky above, the entire ocean is lit up. I have a ton of dives at Lobos, and it was still nice to see a certain area and say, “Wow that’s what it looks like in it’s entirety.”

Not too long in the dive, teams start to separate and head their own way. Our team consists of Kevin, Christian, Tim and I and we continue to Hole in the Wall. As we round the rocky reef just passed Hole in the Wall, I spy a 3′ leopard shark. I enthusiastically wave down my dive buddies and point out the shark chilling on the ocean floor. Kevin says that my shark motion was so enthusiastic that he thought I saw a great white.

Most leopard shark sitings are fleeting, however this one is different. The shark allows for pretty close encounter and doesn’t move an inch as four divers hover nearby. We effectively swim 270 degrees around the shark, without causing a stir.

Kevin circling a leopard shark

After the shark, we reach turn pressure and head home. Kevin leads our team to Middle Reef and we meet up with Itchy, the male wolf eel. His head gets bigger every time I see him. Kevin and I insure that the Christian and Tim get a chance to look and then we kick home.

Doffing the sidemount tanks is easier, but still cumbersome and finger numbing. If I choose to dive the tanks again, I’ll definitely replace the D-rings and bolt snaps. I’m tempted to try AL80s as well, but the prospect of wearing another 12 pounds on my waist isn’t that enticing.

Second dive, we plan to scooter to Beto’s. After two 25/25 dives to Beto’s, this will be my second 32% dive to the reef.

This time donning, I need assistance. Kevin swims over and even remarks that it’s hard. Probably just to make me feel better.

As we surface scoot out, the visibility in the cove has decreased. At the worm patch, the water is no longer clear and viz drops to about 30′.

After a little coordination and corralling by Kevin, our entire group of divers arrive at Beto’s. You can see Kevin be a model diver by checking his gas and then checking the team at the destination. Sorry for the last scene on the video, my camera must have gotten narc’d at the deeper depth.

At Beto’s, Kevin and I look for the wolf eel and the ling cod guarding her eggs, but both are no longer there. Though we miss our animal friends, there’s still a lot of Beto’s to see. Both Kevin and I take turns swimming through the crevices and cracks of Beto’s.

Don swimming through Beto's

After 20 minutes of wandering Beto’s, we head home. With additional SoCal divers with us, we make a return trip to Middle Reef to visit our wolf eel friend.

By the time we reach our 20′ and 10′ stops, I’m very low on gas. As the result, I do an automatic weight check and could add a couple of pounds to be extra comfortable. However, as is, the weighting is pretty good.

Basic Sidemount Class – Day 3

Day 3 – OW and Cave

“Practice only makes permanent. Only perfect practice makes perfect skills.”

For the third day, we headed to Minotauro. Through out our trips back to Mexico, Minotauro remained one of my favorite systems. And it was also one of the systems that challenged us during our Full Cave course. As the result, I was very eager to sidemount this cenote.

The upstream area is a large circuit, with jumps to nearby cenotes. The first 10 minutes is restricted and begs one to tackle the cave with precision. Elissa compares diving it to a rat in a maze, but I enjoy this type of delicate and deliberate diving. After the restricted beginning section, the cave opens up. Each room is distinct and offers a variety of things to look at – from formations to breakdowns to halocline.

Soon after we arrived, two other teams appeared at Minotauro. For such a small system, it was going to get very crowded. Our first dive was planned for main line penetration and I was number two.

Cenote Minotauro

Getting into the water proved to be a non issue. With backmount, the path into the water was precarious. You perched yourself on a rock’s pointed edge while holding onto a very unstable branch. With sidemount, all surfaces became available, and there’s no need to teeter about. We easily placed the stage bottles in the basin, away from the entrance, and then geared up. Because of the lack of surface floatation with the Razor harness, each of us commandeered a rock as we ran through our match.

As we descended, I struck my primary – only to see it not strike. I was very gentle with my lighthead but every year in Mexico the MR11’s bulb breaks. This trip was no exception. After I climbed out, borrowed a screwdriver from Bil Philips and then took Steve’s primary light, we were back in business. If I had struck the light before descending, I would have saved the team some time.

With S-Drills completed, we headed into the cave. The challenge for Minotauro was to not touch anything in the system. I had high hopes for my first sidemount dive in Minotauro, but it was not meant to be. I was too negative. To counteract this, I added more air in my drysuit. Given the <10' depths and the tight quarters, air ultimately migrated to my feet and I had a solid fight for next 10 minutes. Once through the restrictions, I corrected the bubble in the drysuit and let out a sigh of relief. We proceeded into the cave and encountered the circuit closed. The tie into the mainline was different than we were used to so the team paused and conferred on direction. The other team had tied into their own cookie, between the stalagmite and furthest into the cave arrow. jump example

A few more minutes and our team leader turned the dive. We exited the cave without issue. As I am less negative and have less air in my drysuit, the exit through the restrictions felt somewhat magical. Not even the slightest contact with the cave. I felt like I could just think of where I wanted to go and I would be there.

Before getting out of the water, Steve had additional skills for us. We were to handle failures of our equipment underwater. Each of us took turns dealing with a broken bungee and failed tank connections/bolt snaps. The simplicity of the Razor harness made these repairs quite easy.

After lunch, I would be number one. Steve had seen my discomfort through the restriction and suggested that I drop a couple of pounds and perform a weight check. With my weighting sorted out, we got underway.

This time around, the first 10 minutes was very entertaining. The ease I felt on the exit was duplicated on the entrance. I couldn’t stop smiling underwater as I compared this trip to my backmount entrances.

Per our dive plan, I closed the circuit and then jumped to a nearby cenote. En route, we passed a restriction that required each of us to tilt 45 degrees to fit. One downside of sidemount was the wider profile. Narrower restrictions required tilting up to 90 degrees to slip through. Even though these maneuvers were not difficult to execute, I am far from pretty and still worry about the cave.

We then reached the “Sandwich Press,” which really lived up to its name. In backmount, it would have been work to get through. But in sidemount, I was surprised how much space was available. As I swam through, I started making future plans to take my backmounted friends here.

On the opposite side, we turned the dive. As soon as the team faced our exit, Steve signaled lights out. What laid ahead was a no viz exit through the Sandwich Press and the 45 degree restriction. The one thing I really liked about Steve’s courses was the repetition of skills and repetition in different environments. By the time I was going through this final restriction, I was very comfortable in a no viz situation with sidemount.

As soon as I popped out the restriction, Steve has us turn on our primaries. Just as I assumed we were done with drills, Steve told me I was OOG. I turned to #2 and signaled OOG.

#2 donated his primary to me. But as soon as he reached for the extra hose, it was trapped. Since I have an air source, there’s no rush. We took our time to fix the trapped hose and were soon underway.

At the jump, I signaled that we should leave my spool in place and exit. Just as thoughts of Steve picking up my spool crossed my mind, the drill ended and I had to clean up after myself. We finished the dive without any additional issues and surfaced.

During the debrief, we discussed my jump and spool usage. I tied into the other line as follows:
Example tie into other line

A different method was offered, and Steve firmly stepped in and provided his input. Usually Steve allowed for a healthy discussion between the team members, but on this occasion, Steve planted his foot down.

Regarding the OOG, Steve noticed that my teammate’s set-up was incorrect out of the water. In the water, this led to a trapped hose. Once it was confirmed trapped, Steve just waited for the right opportunity to strike. Our S-Drills failed to catch this issue since we don’t fully deploy the long hose, so this is something to be very mindful of.

We concluded the course with Steve providing an individual critique and recommendations to dive the rig as much as possible.

While the sidemount rig proved deceptively easy to dive, there was a good amount of new skills to learn and master. While I am far from perfect, I appreciated Steve’s method of doing skills in multiple environments and situations – building the foundation and confidence for future dives. Overall, the course was a great introduction to the sidemount diving and I really can’t wait for more.

Read More:
Basic Sidemount Class – Day 2
Basic Sidemount Class – Day 1

Basic Sidemount Class – Day 2

Day 2 – OW and Cave

“This is a sidemount course, not a cave diving course.”

In the morning, we met at Cuzel and loaded Steve’s truck. I took great pleasure in just loading single AL80s versus manifolded doubles. Not only was transport less straining on the body, but manipulating the single tanks on the truck was easier as well. Only thing we took care of was keeping the left and right tanks matched.

Cenote Ponderosa, February 2009

After a detour to Pemex for coffee and Gatorade, we arrived at Ponderosa. Danny was there with a Cave 1 course, and everyone exchanged morning greetings. While setting up our sidemount gear, I caught a few of his students curiously looking over.

Don’t blame them, I look over at different gear all the time. Last year, at Ponderosa as well, there was a dive team from Korea that had the 94# OMS wings. They fully inflated on the surface and I could not stop staring. (Side note: Elissa read this and called me a DIR snob. But that’s like the pot calling the kettle…)

Before today’s briefing, we first needed to make final adjustments on weights and harnesses. One of my classmates added a couple of pounds. I decided to try it with my existing weighting (6#s) and then check at the end of the dive. Since this was my first dive using only my drysuit for buoyancy, I was reluctant to add any additional weight unless absolutely necessary. Floaty feet is tiring.

Once our gear was set-up, Steve briefed us on the day’s activities. Steve emphasized this was a sidemount course, and not a cave diving course. As the result, we’ll be spending a significant amount of time in the open water. First with kicks and positioning, next will be S-drills and sidemount skills, and last we’ll be put on a circuit for individual and team work. If our OW work is satisfactory, we’ll conduct a cave dive and practice many of the skills again.

Steve then proceeded to set up a line course above land. My classmates and I looked at each other and nodded – lights out, air-share egress. But before we began, Steve reviewed touch contact signals. Interestingly, but not surprisingly, we had some different signals. For example, I used one firm squeeze for Hold but no signal for OK. The cave instructor was taught one firm squeeze for Hold and two squeezes for OK.

After agreement on signals, Steve taught us “bump and go” no viz exit. Instead of touch contact, each diver was independently on the line. The last diver on the team initiated movement by bumping/pushing the next person in front. This person moved (or bumped the person in front). The team waited to be reunited after a tie or a long period of time. Then bump and go repeated until viz returns.

We then practiced on the line. Each us took turns being 1, 2, and 3 and different “issues” were encountered on the land drills. We repeated everything in cave class for no viz movement.

I still made a bad call though. When my teammate #3 was missing, and teammate #2 went back to check, I (#1) failed to go back. I assumed that it was an entanglement and with my sidemount enabled independence thought it would be better to stay put. Pile up and mass entanglement ideas flashed in my overactive mind. While it was an entanglement that trapped #3, it could have been a directional change that both myself and #2 had missed. As the result, rejoining the team would have been the better decision.

After the review of the line work, it became obvious that #2 played a significant role in the communication. And it was he that dictated a lot of the team’s movements and actions. A failure of #2 to communicate would have disastrous results.

A classmate volunteered to clean up the reel and we proceeded to stage our tanks. At the edge of the platform, I incorrectly situated my tanks and Steve corrected me. We were told to gear up and given 15 minutes to get a feel of the sidemount configuration before we conduct the skills work.

Surprisingly, putting on the sidemount bottles was as easy as attaching stages. I had read about sidemount divers struggling putting on their tanks, but with Steve’s harness this was a non-issue. Left on first, route the hose. Second on last, route the hose. It required a few more minutes to set-up, but the only thing that required muscle was the bungee that held the tanks in place.

With only my drysuit for buoyancy, staying comfortably on the surface with full tanks was not a possibility. Steve stated that sidemount is optimized for in-water movement, and not for on-water comfort. As my head bopped in and out of the water, I definitely agreed. Finding a rock became a priority.

In the water, my initial discomfort immediately disappeared. The freedom and flexibility of the configuration was exciting. While the battleship stability of my backmount set-up was gone, the sidemount rig was instantly balanced. I expected to have trim issues, and was pleasantly surprised that this was not the case. With the tanks, the ballast and buoyancy device at the midpoint, things were very stable. As I looked at my fellow classmates quietly hovering in the basin, I knew that they were happy as well. The feeling of a balanced rig was simply amazing.

After flexing my spin and rolling my neck and shoulders a few times to flaunt the lack of a backplate, I swam about Ponderosa. Fortunately, my turns and kicks still worked. With the baseline functional, I knew that I could focus on the new sidemount body positioning and skills.

Elissa usually teases me that I am a teacher’s pet in class. This time, I can say that I was not. The classmate who was also a cave instructor was very comfortable in the water and was already swimming upside down, and then on his side, and then at a 45 degree while upside down. I looked over at my other classmate, a professional videographer, and he too was swimming with ease.

Not to be outdone, I tried turning laterally and holding position. The sensation of being on your side and not have your tanks try to turtle you is quite refreshing. If anything, it was the bubble of my drysuit that kept me on my toes. The tanks themselves felt stable in almost every position I tried. It was getting a little ridiculous, and I could sense that we were all getting high on these 15 minutes of play.

But before we could get too big headed, Steve appeared and directed us in a series of skills. We formed a semi-circle around Steve and proceeded with basic propulsion methods – frog, helicopter, and backwards kick. Then Steve demonstrated sidemount specific positions and movements and asked us to emulate – slowly. These were lateral rolls, vertical rolls, and then swimming rolling laterally and proceed to swim upside down. While my classmates seem to be doing fine upside down, I had a hard time determining how to stay at the same depth. 10′ forward was okay, but 10′ feet more and I’d lose (or gain) a few feet.

After kicks and positions, Steve had us manipulate our equipment and pouch contents. Steve stores his gear in the back, while I divided items between the back and in my thigh pockets. In order to reach my thigh pockets with dry suit rings, Steve recommended that my way between the tanks. My first timid attempt proved unsuccessful, and later attempts I just jammed my hand in between. Definitely more difficult and time consuming than manipulating the items attached to the back. On on drill, I tried to cheat by pulling an item from my back instead of the requested item from my pocket. I was told to do it correctly.

Once we proved competent in taking out and replacing items with both hands, we moved onto tank clipping and unclipping. Steve’s harness has a unique feature that allows the AL80s to be reclipped on lower D-rings when the tanks become lighter. While diving stages, I’ve clipped a lighter stage on the crotch D-ring or used the SPG to hold the stage down. However, I found these mini D-rings quite practical and very simple. Unfortunately, clipping and unclipping for me wasn’t pretty. Ultimately, I had to do one tank at a time. Steve and the cave instructor classmate manipulated both tanks at the same time. I obviously had very weak thumb strength.

Don in sidemount

At least I could clip and unclip (and Steve would tell me to keep repeating it at every break), so we started our safety drills. First up was regulator exchange. Then we did S-Drills. First individually, and then alternating as a team. With a dive light mounted on the helmet, deployment of the regulator requires an additional step. The videographer classmate had some issues with the S-Drill, so we proceeded to practice this until he had it down. During the debrief, he was clearly disappointed in himself. However, I too have had frustrating issues during class (my stage class in particular comes to mind), so I totally get the disappointment.

We then do valve shutoff drills. With the tanks in front, it’s obviously much easier than backmount.

We surfaced and debriefed. Steve asked each of us to replay the dive and critique the experience. Overall, my classmates and I were impressed with sidemount. The freedom and ease of movement was really unexpected and quite exciting.

The second part of OW involved a circuit. Without thinking I quickly dropped down and found myself as the first student underwater… floating right next to Steve. He pointed to me, pointed to the line, and I took off my mask. Since we’ve had plenty of practice in no viz exits (it felt like half my cave courses were spent lights out and sharing air), I wasn’t initially concerned about the circuit. In retrospect, I should have made sure that I’m not the first in the water or next to the instructor.

On the circuit, as soon as I touched the first tie, it popped off. As I re-wrapped, Steve knocked the line aggressively. Fortunately, I was holding for dear life and the line remained in my hand. Soon, everything started to come apart. I won’t give away too many of the details, but any that could be turned off got turned off, each piece of gear that could come loose came loose, anything that could get entangled got entangled. I thought that things were going okay until Steve knocked the line the third time! I was in the middle of donning some gear and I must of showed weakness. I felt the sudden pressure on the line and gasped as it slipped from my fingers.

There I was in the middle off the water column and no reference. All I could do was slowly descend and sweep my arms side to side. I expected to hit bottom and then conduct a lost line search (while cursing myself out). Fortunately for me, as I descended, my arm hit the line. I was right on top of it (thank goodness). After a moment to regain composure, I attempted to close the circuit without dying.

With the circuit closed, I was handed my mask and got the opportunity to watch my classmates. It’s interesting to see how others handle the same or similar situations. The cave instructor classmate was super speedy when he’s on the line with no viz. Even sans fins, he swam faster than me.

Once the individual trials were complete, we performed team no viz exits. Like the lands drills, we conducted three runs with everyone rotating position. To demonstrate that we won’t endanger ourselves in the cave, we encountered a good number of issues – lost and entangled buddy, multiple unmarked jumps and intersections on the line, etc.

At one of the more confusion intersections, I was #2. #1 had made a decision and kept wanting me to join him. #3 was pressed against me wondering why I was taking so long. All the usual tricks to determine the mainline wasn’t working, and I had to redo them again. And once I made a decision, I took my cookies to mark the side that I came from, but I couldn’t connect the bolt snap to my shoulder D-ring. As the result, I used the entire cookie holder as my personal marker on the line. Even though we were in OW, the pressure was quite strong.

After the team circuits, we debriefed on the surfaced. Steve then asked about our gas, and confirmed that we were switching tanks appropriately. All of us had left and right tanks within 300 psi of each other. Maybe this switching isn’t going to be too bad.

We then replayed the entire dive and Steve asked for everyone’s critique. Steve has a photographic memory with regards to the things that transpire underwater. While I might forget a mistake (I remember big ones very vividly, but little ones only part of the time), Steve definitely does not. Steve would say something like, “And what happened on the second tie?” And my response would be something like, “Oh, yeah…” and smile very broadly as I remember. As one of the many takeaways, I have to work on my no viz, locking re-wraps.

With two OW dives complete, we broke for lunch and geared up for our first sidemount cave dive.

Sidemount tanks

Our first dive, the River Run. The plan is to penetrate the cave on the mainline, and once the dive turns Steve will throw a bunch of issues at us. Once the issue(s) are resolved, we would get back to pre-incident team order.

Our team reviewed that plan, and I was #3 for the dive. After some sorting of how we wanted to do a match, to got underway. Since we never dove together, even just the equipment match took more time and required more communication than my regular team. In addition, since I had contents in my left and right thigh pockets (a deviation from the team standard), this added to some of the extra communication.

In the water, we did flow checks and then attempted to match cylinders. We each had our own way of calling pressure and turn until Steve set us straight. Everyone needed to say their current pressure, the team magic number (the agreed 1/3), and then our turn pressure. This was for one tank at a time. In this slow and methodical method, we were able to validate each other’s calculations (and we caught a math mistake on a subsequent dive).

After gas calculations, our team dropped and conducted S-Drills. We then proceeded into the cave entrance. After the secondary tie, teammate #2 sank to the bottom – his BCD not providing enough buoyancy. Steve and him exchanged signals and they ultimately worked it out. At this time, I’ve been hanging at 45 degrees (following the contour of the cave) and air had been slowly migrating to my feet. Fortunately, before I spazzed out, we got underway and I’m able to adjust.

Within the cave, the sidemount rig remained stable and easy to manipulate. The most enjoyable part was my ability to look straight ahead and still remain perfectly horizontal. In backmount, if I was truly horizontal, I lose some ability to look straight ahead. The manifold is usually in the way. I’d usually have to contort my body a little or break horizontal trim to get full vision straight ahead. Otherwise, I’d be looking slightly down and I would only get limited vision of the top of the caves. With no manifold in the way, my neck was free to arch back.

While sidemount was proving to be good, our team communication was not. As #3, I swam through a good amount of disturbed halocline and at one point almost overtook teammate #2. The addition of new gear and not thoroughly discussing team positioning and communication was having an effect on our diving. In no way were we dangerous, but enjoyment of the dive was reduced for everyone involved. While they were mostly efficiency issues, it’s amazing how it did change the comfort of the dive.

Near our agreed upon turn pressure, #1 slowly helicopter turned. He made a signal that was hard to distinguish in the halocline, so when I swim up, I flashed thumbs. We were all thumbs and began our exit.

A couple of minute passed and then there was a flashing of light. Not the usual broad emergency flashes and not the slow tight flashes that we use to highlight an arrow or something of interest. The flashing was tight and fast.

I turned around and #1 was OOG. #2 and I arrived at the same time but since I had my primary extended, #1 got on my regulator. We get into the appropriate position and continue with our exit. After a minute, Steve called off the drill and I restowed. Instead of having team watch over me, I signaled ok and they swam ahead (yeah, not smart on my part and not vigilant on theirs).

Shortly after, I was OOG and was donated to. Once that was resolved and the donater stowed (this time the team stayed together better), #2 was OOG. As the result we each got an opportunity to be OOG as well as the donater.

Another minute of swimming and Steve called lights out. As we switched off our primaries, the darkness enveloped us. However, with no one in touch contact, it’s really lonely. As I am now that last person exiting the cave (we never did follow Steve’s instruction of resetting the team order), I started our team’s movement by swimming forward and bumping up against my teammate.

Bump and Go exit proved to be very fast, but I did miss the company. Hitting a tie and then meeting the team was on the other side was a welcomed feeling. We exited the rest of the cave in this manner, and I appreciated all the practice time in the dark.

At our safety stop, we watched each other do a valve shutoff drill.

On the surface we debriefed. Again we checked air and confirmed that we did switches even during the no viz exit. And again, the dive was reviewed in detail. Steve especially noted our poor team cohesiveness, communication, and ability to follow instructions. While we were to learn to dive sidemount and not cave dive, it was the actual cave dive with a new teammates that proved difficult. Weighting and buoyancy was also discussed, and we’d be making small changes for the next day to make sure that we’re squared away.

We left Ponderosa as they are closing up for the day.

Read More:
Basic Sidemount Class – Day 3
Basic Sidemount Class – Day 1

Basic Sidemount Class – Day 1

This past February, I took a cave diving sidemount course with Steve Bogaerts.

I’ll profess that it was curiosity rather than necessity that got me to sign up for a sidemount class. While I do like to peek my head into small holes, I have plenty of backmount friendly caves yet to explore. However, the possibility of staging cylinders instead of carrying everything on my back was of interest. I’m lazy and only getting older every day. Plus this definitely has its perks for more remote sites where hiking tanks into the uneven jungle is the norm.

The selection of instructor was easy. As Steve conducts his exploration in sidemount and admits to staying up at night thinking of how to dive sidemount better, it made a lot of sense to take the course with him. Plus, Steve had trained me from Cavern to Full Cave, and is an exceptional instructor. My wife hearts Steve as an instructor and I have to convince her to take classes from other people, it’s becoming a small issue.

In our previous courses, we have always found Steve thoughtful, demanding, and very thorough. What we particularly liked was that his courses follow the format of him teaching, us learning, and then us repeating. During the course, you work on the skill until you’re comfortable and have proficiency.

While his courses require more time commitment than others, it allows for the skills to really sink in. And it doesn’t pressure one to “practice for the class.”

Day 1 – Theory and Equipment

“Just hanging tanks on the side of your body does not make you a sidemount diver!”

The day started at 9am at Cafe Ole in Puerto Aventuras. We then proceeded to Steve’s place for lecture. There were three students in class, including myself. All of us were active divers – one taught and guided locally in the area.

My last trip to Mexico was in November, but have been diving on a weekly basis at home in Northern California. Normally, I would have preferred to spend a day before to sort any issues out with equipment or weighting. But since sidemount was completely new, I decided to forgo any pre-course configuration work. Or at least this would be my rational if I really flubbed the course.

Day 1 plans were to conduct theory, work on equipment, and then proceed into OW. After introductions, we gathered around Steve’s kitchen table and began the theory section. For the next 4 hours we discussed the history, then the whys, the hows, and the what ifs of sidemount diving.

Steve has 3 sidemount courses – Basic, Advance and Exploration. Basic focuses on diving the sidemount configuration and performing all necessary cave and self rescue skills in the new set-up. The expectation is that Basic sidemount graduates dive in the same backmount friendly caves (most likely with mixed teams) for at least 25 dives before moving to Advance. Advance course is focused on skills required to dive only sidemount accessible passages. (Hans has a detailed advance sidemount class report.) Exploration course is … exploration skills and techniques.

The Basic, Advance, and Exploration curriculum is a departure from the 2-day specialty course that’s offered by most agencies. Even after my 3 day Basic course, I can’t imagine trying squeeze through sidemount restrictions. Okay, I can imagine trying to squeeze through the sidemount passages. But in no way could I be confident that I’ll be able to do it safely if an issue arises and without significant effects to the cave itself. Ok, I’ve been tempted to stick my head in and look around in my sidemount rig but that’s it, I promise.

The theory section began with history – UK to Florida to Armadillo to Nomad. Each sidemount style and configuration was developed to tackle the environment they were diving and was a reflection of the biases of their originators.

We then proceeded to discuss the pros and cons of backmount, independent doubles, and sidemount. Not only from a gear perspective but from an individual and team perspective as well.

After this comparison, we delved deeper into sidemount specific details – safety skills, gas usage, weighting, tanks, buoyancy requirements, trim, etc. In each area, Steve offered the pros and cons of the various techniques and ideas as well as offering his preferred method. In these discussions, it was apparent that I was receiving years of knowledge and thoughts on the subject matter.

It was good to review each component in detail, as it forced me to consider things that I didn’t rationalize before. For example, we discussed 200 Bar vs 300 Bar DINs, and the preference for 200 Bar. I’ll admit that I like 300 Bar DINs manifolds, but for cosmetic reasons only.

With theory complete, we took a lunch break and prepared for equipment discussion and set-up. In retrospect, I should have asked even more questions during theory. However, since everything was quite new, it took a little for me to absorb and process. Fortunately, there were 2 more days of class.

Equipment took the rest of the afternoon. Only one student came prepared with harness and helmet rigged. At least I had my regs in order with the proper hose lengths. Everything else was either in plastic wrap or had to be constructed.

First thing was tanks and regs. In the Basic sidemount course, the regulator configuration is quite similar to Hogarthian backmount set-up. There’s a 7′ long hose as wells as a short hose with a necklaced regulator. The benefits when diving with mixed team is obvious – the OOG procedure remains exactly the same.

Next, we tackled helmets. After initial comparisons of each others’ helmet choices – construction, climbing, and kayak, we began work. Steve provided a drill, a jig saw, some PVC piping of various sizes, sandpaper, and plenty of zip ties. Since I like tinkering, this was a lot of fun.

Steve's sidemount helmet

Following Steve’s instructions and details on why he set-up his helmet, we started fabricating. Measure twice, cut once and soon we were underway. In the end, I failed to tighten my zip ties enough (did not use pliers to really tighten). But overall things looked good on land.

Once helmets were sorted, we proceeded inside to put together a Razor sidemount harness. All three of us elected to use Steve’s harness for class. Even though basic set-up is theoretically similar to an Hogarthian harness, it felt like I was getting clothes tailored. Steve more or less measured the harness length and made adjustments to plates and D-rings while I stood in the middle of the room. Since one of the students already had his Razor sidemount harness built before class, he assisted our other classmate in kitting up.

The entire adjustment process felt like the first day of an Essentials or Fundamentals course. Check harness tightness, check the D-ring positions, and adjust as necessary. All of it ends with the ceremonious and familiar burning of the harness ends.

Steve helping adjust the Razor sidemount harness

With our gear sorted, we were ready to hit the water. By now, it was late in the day and a trip to Ponderosa was unlikely. We opted to do some basic weighting and swimming in Steve’s communal swimming pool. In 3′ of water, we got ourselves situated as best we can.

While my weighting appeared good, it was obvious that my kayak helmet was too buoyant. It’s an odd sensation to have your head being lifted to the surface while your body wants to stay submerged. To take care of the issue, I ripped out most of the padding. With minimal padding remaining, the helmet was now neutral.

After getting personal buoyancy dialed in at neutral, we donned tanks and started to play. Once submerged, it was obvious that all of us immediately enjoyed the sidemount set-up. I couldn’t help smiling while doing backwards kicks, helicopter turns, and frog kicks around the tiny pool. Following another classmate’s lead (I’m only slightly competitive), I did S-Drills, and then started to manipulate my tanks.

Out of the water, all of us were beaming. If things were this good in 3′, we couldn’t wait for the upcoming days.

We concluded the day by finalizing weight requirements and insuring that each of us make the necessary modifications to our gear that we did not complete during the day. Tomorrow, we meet at Cuzel.

Read More:
Basic Sidemount Class – Day 2
Basic Sidemount Class – Day 3

Cave diving in sidemount

Don in sidemount

I signed up for a sidemount cave course with Steve Bogaerts, and first impressions are amazing.

One thing about sidemount – it’s a very liberating way to dive. Hadn’t thought of how it’d feel to dive in sidemount much. I had only considered it as a tool for tighter passages. The one thing I kept hearing was that it’s extra task loading to gas balance the tanks.

As such, I had very little preconceived notions before getting in the water.

It really surprised me how free I felt. Steve’s harness is very simple and well thought out. As the result, the tanks are snug against the body and there is little or no “swing.” While diving stages, this is one of the annoyances. The stage tanks momentum is separate from the body, and movement occurs with every kick.

With the rigid backplate gone, the spine and shoulders feel light. With no tanks and manifold behind me, I can look straight ahead in prone position.

I need more in water time to be proficient, but there are just things that I can do now that I wouldn’t have considered in backmount. For example, swim on my side. Should be able to rotate laterally and hold any position. I’m not quite there, but it’s only been a couple of days in the water.

There is more complexity (equipment and logistics) in the system compared to backmount, but in water performance is quite remarkable. Definitely a valuable tool, but I don’t know if this will become a regular kit. At the end, it’ll really depend on the dives and systems.

After my 4th post course dive:

EL’s first dive ever in sidemount: