dry suit diving techniques. objectives to develop the student’s knowledge of dry suits - when to...
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Objectives To develop the student’s knowledge of dry
suits - When to use dry suits, types of dry suits available, their maintenance
To develop the student’s ability to perform effectively in a dry suit
To enable the student to plan, organize and conduct SAFE operational dives
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Minimizes Exposure to: Gasoline & oil Sewage & waste water Agricultural run-off Human tissues/body decomposition Bacterial infection
Thermal Protection With proper insulation, dry suits provide
excellent thermal protection in cold water.
Wet Suits (Foam Neoprene) Insulating ability determined by thickness of
suit Insulation and buoyancy
DECREASE with INCREASING DEPTH Allows skin exposure to contaminants Allows water against skin (Cold) Requires a good fit Must dry before repair
Dry Suits Control of insulation and
buoyancy regardless of depth No skin contact with water No increase in air consumption Rugged, longer life, more
durable Variable insulation options Does not require perfect fit Can be repaired quickly
Thermal Comparisons
# of Dives/
H2O Temp
Wet Suit Dry Suit
1st 2nd 3rd 1st 2nd 3rd
700F 100% 100% 100% 100% 100% 100%
600F 100% 90% 80% 100% 100% 100%
500F 80% 70% 50% 100% 100% 100%
400F 50% 25% * 100% 85% 75%
320F * * * 100% 75% 55%
* Not recommended unless involved in a life-saving rescue.
Modern Dry Suit Construction Crushed neoprene Coated or laminated fabric Polyurethane laminate Vulcanized rubber Other special design (military)
Vulcanized Rubber Dry Suits Offer
Good environmental protection One piece construction Inflation/exhaust valves Rugged and flexible Attached boots Dry hood
Polyurethane Offer many of the same benefits of
a vulcanized rubber suit
Fast and simple to repair
Slightly less flexible than rubber suits
Lighter weight than rubber suits
Dry Suit Care Lubricate neck and wrist seals with talc Wax zippers, store open Wash and thoroughly dry inside and out Inspect for tears in seals Inspect valves Avoid exposure to UV rays,
oil & harsh chemicals
Donning Determine need for thermal insulation Smooth neck and wrist seals against skin Zip closure Check exhaust valve Crouch and “Burp” Attach Low Pressure hose Check inflator valve
Diving Equipment Considerations Weight systems Buoyancy Compensation
Devices (BCD’s) First stage regulator
(L.P. ports) Fins
Important Features Attached boots Attached hoods Waterproof zipper Attached gloves (cuff rings) Reinforced stressed/abrasion points
Maintain Proper Positioning Maintain head up/feet down
orientation Control buoyancy with BCD Add air to dry suit to prevent
squeeze Vent excess air through
exhaust valves to prevent uncontrolled ascent
Dry Suit Diving Requires Control and Composure
Dry suit operations require a strong foundation of basic scuba skills on
which to build advanced level skills.
Knowledge of dry suit operations will help avoid potential
emergenciesLearn the specific emergency
procedures for these situations.
Emergency Procedures Inflator valve stuck open…
Disconnect L.P. hose Assume proper position and utilize exhaust valve If severe enough allow air to escape by releasing
neck or wrist seals (WATER IN) If air cannot be vented, utilize “FLARE” position
Emergency Procedures Inflator valve stuck closed…
Stop descent and terminate the dive Use BCD as needed to control buoyancy Return to the surface venting expanding air as
normal
Emergency Procedures Exhaust valve stuck open…
Determine the extent of leak Terminate dive Exercise the valve Increase valve spring pressure
Emergency Procedures Exhaust valve leaking…
Determine extent of leak Terminate dive Use BCD in controlling buoyancy as needed
Emergency Procedures Exhaust valve stuck closed…
Control ascent by pressing exhaust Valve to allow expanding air to escape or use “FLARE” position if air cannot be vented
Use ascent line if available
Emergency Procedures Inverted position from air in the feet…
Forward swim-out roll (Tuck & Roll) Backward swim-out roll
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Emergency Procedures Inverted position from air in the feet…
Forward swim-out roll (Tuck & Roll) Backward swim-out roll
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Emergency Procedures Loss or failure of air supply…
Control ascent rate by venting air from suit as you ascend
Venting air by manually activating exhaust valve may be required
Emergency Procedures Flooded Suit…
Use BCD to control buoyancy If additional buoyancy is needed, drop weights Control buoyancy by venting suit or BCD as
needed; suit may maintain a large volume of air Attempt to minimize the effect of leak by
positioning it low if possible
Emergency Procedures Dropped or lost weight belt or weight
system… Attempt to recover weights If unable to recover weights, control ascent by
exhausting air from suit with valve If unable to release air from the suit, or ascent is
too rapid use the “FLARE” to control ascent