Deep-Sea Sherpa

In many basic Open Water scuba courses, divers are taught vertical body position for ascents and descents. While there are some benefits to this technique, a horizontal body position is safer, more effective, and much easier to execute.

Body Position
The prone body position, preferred while diving, is also the preferred body position for ascents and descents.

Below is the prone/horizontal/skydiver body position:

Below is the vertical body position that most divers use for ascents and descents:

Drag
The horizontal diver position provides a significant drag in the vertical water column. The wider profile helps control buoyancy as well as slows the rates of ascents and descents.

The vertical diver position provides less drag in the water column. As the result, it takes more effort to maintain position and rates of ascents and descents are faster.

The above illustrations are from the side profile. However, viewed from the top, the profile differences between the horizontal and vertical positions is even more dramatic.

For descents, it’s usually easiest to descend the first 2′-3′ in vertical position since it’s the most steamlined. Once the surface tension is broken and compression starts, then the diver switches to a horizontal position to help control the descent rate and allow for maximum mobility.

Platform
Because of the benefits of drag on the horizontal driver, this position offers the most stable platform. This stability is particularly useful if the diver becomes task loaded or needs to resolve an issue during descents, ascents, or safety stop.

Most diving issues occur during descents or ascents. Even with the appropriate equipment and bubble checks, the descent is when your gear is first being tested. In our local waters, descents are also a common time for buddy separation. During ascents, issues include OOAs and gas switching mishaps. In these situations, the diver needs to be able to maintain neutral buoyancy while resolving the issue. The horizontal position makes this much easier.

Field of View

During the descent, a horizontal position provides optimal field of view. Both positions allow for looking forward at your teammates, but the horizontal position provides a great birds eye view of the bottom.

The horizontal position does limit your ability to look above you. But teams should descend and ascend together, at the same rate.

During ascents, in areas where a total horizontal position ascent may be dangerous (e.g. ships overhead), then switching to a more vertical body position in the last few feet may prove helpful. However, the best ascent strategy is to ascend in teams and have your teammates watch overhead and behind you.

Kicks
In addition to vertical drag benefits of the horizontal body position, the prone position allows quick access to all kicks. These could include the small kicks for positioning the diver with the team and the environment. It also includes large kicks to quickly reach a teammate if there is an issue.

A diver in the vertical position has less horizontal mobility. Kenn (Gombessa on ScubaBoard) notes the vertical position also reduces vertical mobility. In the horizontal position, tilting up or down offers quick adjustments. In the vertical position, moving up is easy but moving down requires a full inversion.

The biggest issue with the vertical position is the use of fins to maintain position in the water column. Not only does this require work (consuming more gas), kicking to control buoyancy is not a stable position. In order to maintain buoyancy or control, the vertical diver must manage the BC and kick a consistent cycle. Alternately, the horizontal diver simply uses the BC or breath control.

In addition, a diver kicking in vertical position has an impact on the environment. On descents, silt and sand can be kicked up by a vertical diver’s fin movement. It’s not uncommon to see great viz, until divers descend onto the ocean floor. Fortunately, this can be eliminated if divers descend in horizontal position with their fins parallel to the ocean floor.

Rate of Descent and Ascent
While there’s generally prescribed rates of descent (slow enough to allow sufficient equalization) and ascent (30 ft/min), the overall goal is control.

Upon reading this article, Ben (ben_ca on ScubaBoard) made a good comment about the need to arrest your descent/ascent with relative ease. He recommends a range for beginning divers of 4-5 ft and advance divers of 1-2 ft.

Not only is this control helpful in managing ascent/descent related issues such as blocks, but it is useful in keeping buddy teams together and being available to help if required.

A good way to practice is to make predetermined stops on descents and ascents. For example, instead of descending immediately to the bottom, agree with your buddies that everyone will stop at 10′ and 20′. On ascents, safety stops can be done at 30′ for 1 minute, 20′ for 1 minute, and 10′ for 1 minute.

How to Descend

Below is high level descent strategy, the diver will need to adjust to local conditions.

1. Signal descent, get confirmation
2. Inhale
3. Dump gas
4. Exhale
5. Confirm legs are not kicking
6. Transition to horizontal position
7. Look at buddy
8. Look at environment
9. Equalize
10. Add gas to control descent speed
11. Repeat 7-10 until hovering comfortably off the bottom

How to Ascend

Below is high level ascent strategy, the diver will need to adjust to local conditions.

1. Start neutrally buoyant in horizontal trim
2. Signal ascent, get confirmation
3. Inhale to start ascent
4. Look at buddy
5. Look at environment
6. Dump gas to control ascent speed
7. Repeat 4-6 until the safety stop
8. Conduct the appropriate safety stop(s)
9. After safety stop(s), continue to slowly ascend until the surface

• Scuba 101 – Controlled ascents
• Horizontal Trim 101 – Uses
• Horizontal Trim 101 – Levers

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How To, Training by Don

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.

Harness
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.

Tanks

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 skills demonstration
• How to Route Hoses on Sidemount Tanks
• Friday, April 17, 2009 – First cold water sidemount dives
• Basic Sidemount Class – Day 3

Filed under:
Training by Don

Cave divers and technical divers extensively use reels and lines. As such, we have standard signals to communicate these items.

“LINE”
This signal denotes a line. Depending on situation, can be the dive team’s line, the anchor line, or a side passage line.

“REEL”
This command can either be the object or an action, depending on context.

Usage Examples:
    Signaler: “QUESTION” + “PICK-UP” + “REEL” = Pick-up reel? Or leave the reel for the next dive?

“TIE”
It is not uncommon that a team member will be in a position to see better tie points. The “TIE” command tells the person with the reel to tie around a specific point or object.

Usage Examples:
    Signaler: “TIE” over a rock = Use the rock as a tie point.

“ENTANGLEMENT”
Sometimes you get stuck. This signal is denote that you or your dive buddy is entangled.

“JUMP”
In order to make a jump, the action needs to be communicated. This sign requires a confirmation from the team before preceding.

Usage Examples:
    Signaler: “QUESTION” + “JUMP” = Jump?
    Teammate: “JUMP” = Confirming jump.

• Scuba Signs – Position in the water column
• Scuba Signs – Deco stop / safety stop
• Scuba Signs – Directions
• Scuba Signs – Issues
• Scuba Signs – Command Signals

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Training by Don

In order to carry necessary scuba diving gear as a carry-on (as well as save a little weight from luggage), Jeanna and Brian of Frogkick Diving made a backpack for their backplate.

For the technical scuba diver, a backplate and pack makes a lot of sense. I saw Jeanna’s design while at the UTD Symposium 1.0.

After seeing Jeanna’s and Brian’s design the prior year, fellow UTD instructor James Mott made his own version – with support for fins.

Even though I joked about it to my wife and Dennis Weeks a few years ago while traveling in Mexico, I never took action. Seeing Jeanna’s design got me off my butt and I made the following from a computer bag. I loose style points, but gain laptop portability.

Filed under:
Equipment by Don

On Thursday, Kenn, Steve, I took a mid week day for a
UTD Stage Mini.

For technical diving, the use of deco bottle or stage bottle is a necessary skill. The UTD Stage Mini allows one to learn how to use a deco bottle in a workshop format. The day consists of lecture, equipment review, dry runs, in water skills, and then post dive review.

Kenn recently acquired a Flip HD with the new Ikelite Flip housing. To increase the viewing angle, he mated it with a wide angle lens. As the result, we had some great video of the day. Definitely watch in the UTD Stage Mini in HD mode.

• Essentials October 2009
• How to mark a stage or deco bottle
• How to rig a stage or deco bottle
• How to clip the SPG to the hip D-ring
• Scooter technique – dumping gas

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Training by Don

As cold water divers move from wetsuits to drysuits in the pursuit of warmth, happiness and dryness many experiences await!

• TecReational Path

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Training by Don

As recreational divers move towards the technical path, they will have many decisions and experiences:

• Drysuit Progression

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Equipment by Don

Okay, this is a total self promotional blog.

As scuba divers, we know that hydration is incredibly important before and during the dive day.

Lately, I’ve been bad to the environment by buying bulk packs of water from Costco. Going through 3-4 bottles a dive day is definitely not ecologically sound (or financially smart).

The alternative was to bring either a Nalgene or SIGG reusable water bottle. Dissatisfied with available designs, I made my own – “It’s Okay, I’m Ninja” with a technical diving ninja (doubles, canister light, and Jet Fins).

I made it available via CafePress, but it’s a little pricey. If there’s real interest, I can consider an alternative source for my It’s Okay, I’m Ninja – technical scuba diving SIGG.

Filed under:
Equipment by Don

Pictures from the UTD Essentials scuba diving class in Monterey, CA this past weekend.

Find more photos like this on Unified Team Diving

• October 30, 2009 – UTD Stage Mini
• How to mark a stage or deco bottle
• How to rig a stage or deco bottle
• How to clip the SPG to the hip D-ring
• Scooter technique – dumping gas

Filed under:
Training by Don

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, climbing helmet, 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.

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.

• The Bogaerthian Configuration
• Sidemount diving skills demonstration
• How to Route Hoses on Sidemount Tanks
• Friday, April 17, 2009 – First cold water sidemount dives
• Basic Sidemount Class – Day 3

Filed under:
Training by Don