Diving Dry
Many divers coming from recreational into technical diving are normally sporting wetsuits. Wetsuits are easily purchased from most dive shops and are much cheaper than their drysuit counterparts. But why might a cave/technical diver consider purchasing a drysuit? I mean, after all, they are very expensive, prone to leak when damaged, and add one more thing to inflate/exhaust during the dive. In addition, it takes a number of dives (usually about 10) to really begin getting comfortable diving dry. Nonetheless, I?ll try to lay out the main benefits of drysuits and hope it will help you decide which route you want to go.
I prefer the DUI TLS 350 drysuit. It?s a shell suit. So it provides minimal thermal protection without undergarments of some sort. I like the front zipper on this one which makes it easy for me to zip myself. The basic cost is about $1,600 for the suit. If you get bellows pockets on each side and a balanced P-valve, then you?ll have to pay for the extras. In addition, you have gator wraps, condoms, fin keepers, KY gel, and undergarments to purchase at extra cost. My undergarment is the DUI 400G Thinsulate. It costs about $400. I also got the footies that go with the undergarment. So you are talking about $2,100 when all is said and done versus a $300 wetsuit. So what are the benefits?
1. A drysuit is easier to don and doff prior and after the dive. You aren?t squeezing in and peeling off the suit like you do a wetsuit.
2. With the exception of the wrist and neck seals, it isn?t as tight either when wearing it.
3. A drysuit dries quicker after the dive.
4. Although you can put bellows pockets on a wetsuit, they are normally found on drysuits. These guys are awesome. You can place spools, masks, etc clipped off inside them which frees up your butt D-ring and looks cleaner.
5. The use of a P-valve is a better option than peeing in a wetsuit.
6. Although using a drysuit as backup inflation for failed wings during a dive isn?t considered DIR, the fact remains that the suit does hold gas, and that fact can provide a last option if you are ever in that situation.
7. Long dives, especially those requiring long decompressions, require being dry in order to stay warm. Getting cold is a recipe for DCS.
8. Really cold water dives are best done in drysuits to keep ALL the water away from your body.
9. You don?t get that cold water running down your back at the beginning of the dive like you do wearing a wetsuit.
10. Diving dry in salt water is nice because you don?t feel sticky from the salt once the dive is over, like you do when you dive wet.
11. You don?t have significant suit compression which alters its thermal protection at depth (especially great depths) like you do with wetsuits. The shell suit?s thermal protection comes from undergarments.
12. Similarly related, the drysuit doesn?t compress to the extent that a wetsuit does. It does squeeze, which is why you have to add gas to the suit, but it doesn?t change to the extent that a wetsuit does. Therefore, your weighting needs don?t change at depth, nor do your arm gauges need adjusting once at depth.
13. The drysuit inflation hose can be used as a backup to your wing inflator hose in case of a failure.
14. The configuration for the drysuit inflation requires that it come off a separate post than does your wing inflator hose. This adds a level of redundancy in case one of your posts is damaged and has to be shut off.
15. Even if flooded, the 400G Thinsulate undergarment is designed to keep you relatively warm even though you?re now wet.
16. Inflation of the drysuit can be done with Argon gas for very long dives which would be more insulating than air. Also, deep dives using trimix would use Argon to inflate the suit because the helium will draw body heat much more quickly than even air.
17. It makes you a lot more aware of your technique when diving dry (i.e. placement of knees) cause you know the consequences of a suit tear is worse than a wetsuit.
18. The feet of the DUI TLS 350 fit snuggly into the XL Scubapro jetfin.
19. Bottom line ? diving dry is DIR!!