Copyright 2012 CFT DS/1 ISO 24801-2 / EN 14153-2 "AUTONOMOUS DIVER" Dry Suits.

Copyright 2012 CFT DS/1ISO 24801-2 / EN 14153-2 "AUTONOMOUS DIVER"

Dry SuitsDry Suits

Copyright 2012 CFT DS/2

We will cover Function and types Suit fit and undergarments Dressing Undressing Suit controls Care Use of B.C.s with drysuits


We will cover Buoyancy and drysuits Suit controls and weights Establishing neutral buoyancy Snorkelling in drysuits Drysuit squeeze After the dive


Function To keep water out To provide insulation

Trapped air Small leakage not uncommon

Through seals or controls


Types

Light weight - Membrane High wear resistance No inherent buoyancy or insulation Dependant on adequate undergarments


Types

Neoprene Same material as wetsuits Capable of stretching Loses buoyancy on descent


Suit Fit Should be closest possible fit

Space to fit undergarments for insulation Built in booties on most suits Prone to ‘squeeze’ Suit inflation maintains comfort


Undergarments Woolly bear Snug fit Thicker for membrane suits Many thin layers best Thermal underwear for neoprene Thick socks if booties fitted


Dressing Latex seals are easily damaged Seals must be fitted on bare skin Dust seals with french chalk or talc Apply beeswax to zip Sit down to fit legs, stand up and pull up to chest Insert hands carefully through seals Stretch neck seal as wide as possible and pull

over head Get buddy to carefully close zip


Undressing Reverse process Wash down outside with fresh water Remove seals very carefully Hang suit up to dry Store by draping at the waist over a padded rail Dust latex seals with french chalk/talc to prevent

perishing Spray booties with silicone


Suit controls To inflate and vent suit To add air for ‘comfort factor’ Some suits, controls are ‘extra’ Should be accessible when wearing B.C. Vent should be high on body Most vents are automatic Inflation by low pressure direct feed ‘whip’ Should be accessible to either hand


Care Seals

Vital and weakest part of suit On membrane suits, they can be DIY replaced

Entry zips Water tight zip vital Position varies Clean and lubricate regularly


Use of B.C.s with drysuits CFT rule

A B.C. to be used always With alternate air source, Preferably mini cylinder

Why? Emergency rapid ascent Emergency buoyancy to escape from depth Recover from an inverted position Alternate air supply


Buoyancy and Drysuits Lightweight (membrane) suit has no inherent

buoyancy Need little additional weight Less change in buoyancy during descent than

neoprene Can become quite uncomfortable from squeeze

Neoprene drysuits have greater inherent buoyancy

Need additional weights Significant loss of buoyancy during descent Little squeeze experienced


Suit controls and Weights B.C. may obstruct access to fill valve

Try combinations to get best match Correct weighting and neutral buoyancy just

beneath the surface are important Excess weight leads to problems


Establishing Neutral Buoyancy Membrane suit with woolly bear

Needs little additional weight In upright position submerge and vent suit fully No significant squeeze experienced

Neutral buoyancy just below the surface


Establishing Neutral Buoyancy Neoprene suit

Needs more weight In upright position, submerge and vent most air Some air required in suit to seal neck No squeeze experienced

Neutral buoyancy just below the surface


Snorkelling in drysuits Membrane suits

Particularly suitable If buoyancy adjustment is correct, squeeze is not a

problem in normal snorkel dive range Neoprene suits

Less suitable Excess buoyancy on surface Loss of buoyancy on descent


Diving Practice surface swimming in neutral buoyancy

Training pool or safe open water - before diving Buoyancy while diving

Maintain neutral buoyancy Too much air in suit affects trim Use B.C. to compensate for buoyancy loss Over inflation

Air migration Risk of inversion


Drysuit Squeeze From 10m down squeeze may be painful To avoid discomfort add ‘Comfort Factor’ of air Add minimal air to ease feeling of pressure Maintain comfort by adding/venting air

throughout the dive


After the Dive Inflate the suit partially

Reduces wind chill Rinse in fresh water

Inside if necessary Hang up to dry


Summary Function and types Suit fit and undergarments Dressing Undressing Suit controls Care Use of B.C.s with drysuits


Summary Buoyancy and drysuits Suit controls and weights Establishing neutral buoyancy Snorkelling in drysuits Drysuit squeeze After the dive

Copyright 2012 CFT DS/24ISO 24801-2 / EN 14153-2 "AUTONOMOUS DIVER"

Questions?Questions?

Copyright 2012 CFT DS/1 ISO 24801-2 / EN 14153-2 "AUTONOMOUS DIVER" Dry Suits.

Documents

drysuits cft

drysuits slide

cft ds14 buoyancy

neutral buoyancy membrane

neutral buoyancy neoprene

surface slide

dive slide

descent slide