 Steve's Library of Articles
NACD Specialty Cave Diver -- Sidemount
 I. MOTIVATIONS.
1. Learning and expanding skills.
2. Convenience of access to difficult locations/entrances.
3. Physical limitations, (such as back problems).
4. Accessing smaller areas of a given cave, etc.
II. PRIMARY ADVANTAGES.
1. Convenience of access to the water, don't have to carry on back.
2. Totally independent gas sources.
3. Lower diver profile, potentially less contact with cave.
4. Ability to access smaller passage of any given cave.
5. Ability to operate alone and be isolated for longer, if separated from the team.
III. MANAGING GAS/AIR QUANITIES.
1. Requires the monitoring of independent gas supplies, to insure you are maintaining an acceptable gas quantity balance in each cylinder. The less difference in gas quantities between cylinders the better, however minimal regulator switching is also preferred.
2. Breathe ½ of a third (if dive is planned on thirds) of the first cylinder, switch, breath ½ of that third, (or sixths) switch back to the starting cylinder and breathe the final third. Make the last switch to the second bottle, breathe that final third, turn and exit.
IV. BEST SELECTION OF TYPE OF VALVES.
1. DIN outlets, opposing valves. This allows access to each valve knob.
V. PROBLEMS ENCOUNTERED WITH ALUMINUM 80's.
1. Positive buoyancy characteristics, especially toward the end of the dive.
2. Bottoms of AL 80's float, and can create stress when backing up in a small passage
VI. IDEAL LENGTH OF REGULATOR HOSE.
1. Any length is acceptable if stowed properly.
2. 28" - 32" is the most ideal for the side mount diver.
VII. POSITIONING OF BCD INFLATOR.
1. BC inflators should be short.
2. The airway elbow should not come in contact with the ceiling, or be on the back of the air cell.
3. Should be short enough to insure the diver can successfully exhaust (dump) air from the air cell, while in a completely horizontal position, such as a tight passage. Vertical relief is not always available to the side mount diver. Dump valves need to operate with the diver completely horizontal.
4. Should be long enough to insure the diver can access the inflator orally.
VIII. METHODS OF PROGRESSION FOR SMALL SILTY PASSAGES.
1. Low limb movement, slow progression.
2. Fingers or hands on the ceiling above the head.
3. Pushing with feet on ceiling.
4. Finger walking.
5. Hands on wall (pull and glide).
IX. WHAT TASKS ARE ADDED TO THE SIDE MOUNT DIVER.
1. Gas management.
2. Cylinder quantity balance.
3. Regulator switching.
4. Potential manipulation of cylinders, in small restrictions (taking off a cylinder).
X. MAXIMUM PENETRATION - ONE TANK UNUSEABLE.
1. Evaluate usable gas in working cylinder.
2. Verify gas (if any) in failed cylinder, for future consideration.
3. Switch to working cylinder, exit small passage, exit cave.
XI. METHOD OF LINE BELAYMENT, WHERE PASSAGE IS SMALL AND WITHOUT PROJECTIONS.
1. ½" PVC stakes help to keep the guideline in place.
2. In small passages this may NOT be where the divers can swim, but may need to be in an area that is only accessible to the divers hands.
XII. PROBLEMS ENCOUNTERED SIDE MOUNT VS. BACK MOUNT.
1. Gas sharing. Side mounted divers don't usually possess long hoses, so the back mounted diver would be at a great disadvantage.
STUCK AND CANNOT MOVE FORWARD OR BACKWARD.
1. Relax. Breath. Breathing control is the benchmark for everything else. Keep the breathing under control and you can get yourself out of most any incident.
2. Evaluate where you are, and how long it will take you to get out.
3. Insure the BC is completely empty of all air.
4. There is always room, you just have to find it sometimes.
RESTRICTION TOO NARROW FOR BOTH OF YOUR TANKS.
1. Remove the tank you are not breathing off of, leaving it attached at the top attachment, and push it ahead of you.
PASSING A RESTRICTION TOO NARROW FOR EITHER OF YOUR TANKS.
1. Remove both tanks, leaving them attached at the top attachment, and push them ahead of you.
PASSING AN AREA TOO NARROW, BUT TALL.
1. Simply convert your profile and swim sideways through the vertical restriction.
TANK TRAP
1. An area in a small passage where the diver can pass, but not with both cylinders. Once cylinder continues to trap under a projection or low area. The tank must then be removed.
SHARING GAS/AIR FROM ANOTHER SIDE MOUNT DIVER WHILE EXITING ON SHORT HOSES.
1. The donor lays on top of the back of the recipient, donating gas from the cylinder that is not in use by the donor.
PLACEMENT OF SECOND STAGE REGULATORS AND WHY.
1. On top or front of shoulders.
2. Easy to access in low areas.
3. Does not drag in the sediment.
4. Neck loops should not be used in side mount diving.
IMPORTANT FACTOR TO THE PRIMARY LIGHT.
1. Being able to remove it and replace it with ease during the dive
CARRY A SPARE MASK.
1. Yes.
2. Sidemount passages yield more contact, there is more of a chance of pulling off a mask, or being kicked in the face in small passages.
THE BEST ATTRIBUTE A GOOD SIDE MOUNT CAVE DIVER.
1. Healthy motivations for side mounting and technique.
IS SIDE MOUNT CAVE DIVING SIMPLY A MEANS TO REACH SMALL AREAS OF THE CAVE?
1. No, it is a style of diving. One that can be enjoyed and perfected, while never entering a small space
Do you feel ready to plan and execute side mounted cave dives?
STUDENT SIGNATURE________________________________________
DATE___________________
Steve Gerrard lives in the Puerto Aventuras marina resort. He has been safely teaching cave diving for twenty five years. His favorite activity is underwater cave photography using the NIKON 100 digital camera with a Light & Motion Titan Housing using Ikelite strobes. He is the author of the famous guidebook titled - THE CENOTES OF THE RIVIERIA MAYA and soon to be published CENOTE DIVING - SAFE & FUN. You can contact Steve at:
stevegerrard@cavediver.com or www.steve-gerrard.com
|
