1. Dry Suits

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

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

4. Function To keep water out To provide insulation
Trapped air
Small leakage not uncommon
Through seals or controls

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

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

7. Suit Fit Should be closest possible fit Built in booties on most suits
Space to fit undergarments for insulation
Built in booties on most suits
Prone to ‘squeeze’
Suit inflation maintains comfort

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

9. 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

10. 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

11. 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

12. Care Seals Entry zips 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

13. 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

14. 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

15. 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

16. 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

17. 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

18. 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

19. 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

20. 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

21. After the Dive Inflate the suit partially Rinse in fresh water
Reduces wind chill
Rinse in fresh water
Inside if necessary
Hang up to dry

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

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

24. Questions?