OCC Forums

Survival suit vs Drysuit


By DariaBlackwell - 29 Nov 2018

I read an interesting article in Practical Sailor in which they compared the benefits of a Drysuit vs Survival Suit for offshore sailors. The conclusion was that Drysuits, the kind used by divers, kite boarders and paddle boarders, are gaining in popularity for good reason. Do you have experience with either on board?

By Dick - 29 Nov 2018

Hi Daria,
I remember when I read this article, I thought it was one of PS’s poorer reports, but I do not remember details of my misgivings now (and it must be said, a poorer report from PS is still a good report).
It may be a definition of terms, but I do not know of anyone who would think to work their boat in a survival suit: aka an immersion suit or Gumby suit (enclosed feet and hands, very big and bulky and hard to move around in). This is a suit you want to abandon ship in, especially in cold water. The closest cousin I can conceive of for working a boat while wearing is an exposure suit where Mustang and First Watch stand out (think of the suits highway workers wear in cold weather (hands and feet free, good insulation and decent mobility, flotation).
Drysuits also differ. You mention diving and that form of drysuit needs to be connected to your tanks for buoyancy control. Drysuits for rafting, kayaking, and I suspect kite and paddle boarders do not need the complexity of valves to adjust air inside the suit.
I carry both a drysuit and a First Watch exposure suit on Alchemy.
The drysuit is a kayak model (no valves) which I got for going into cold waters for, bottom cleaning, zinc changes and for possible prop wraps and the like (I was becoming too cold to work effectively in a double layer of 2-3mil wet suits in less cold water). I use it with a very thick one-piece fleece undergarment. The combination has kept me warm in 6-7C/40+F water for extended periods.
Drysuits are a challenge to get into and out of. I suspect I could do so, but I am glad, at my well into senior age, that Ginger is always around to help. They can be rather fragile, so the exposure to everyday use would likely have them torn or abraded in short order. They are not designed for that kind of use. The enclosures at the neck and wrists are quite tight, The head is exposed, so I use a neoprene dive “helmet” and gloves can be nice depending on the work. Feet are enclosed. I have never used the drysuit for on deck work. I would consider doing so if I needed to be on the helm for long periods in cold/wet weather, but I would not consider it for general wear. It is a dry suit and any real work gets the underclothing quite damp with perspiration. I would always choose good foul weather gear with layers over a drysuit.
For working in the water, achieving neutral buoyancy demands 2-3 times the weight of wet suits. I needed to buy a weight belt with shoulder straps to handle the weight. And drysuits have some special properties that need attention: air can go to your feet inverting (and dis-orienting you). If at all unsure, get some drysuit lessons, even for bottom work, especially if you are not a diver.
My exposure suit was bought with a few uses in mind, primarily taking a line ashore for anchorages in Greenland where that kind of anchoring is called for. I know how easy it is in cold wet weather to fall in the water going from dinghy to a wet rocky shore carrying gear. Falling into 5-10C water in an exposure suit you will still have a chance, while still having the mobility to do the work called for, rowing the dinghy, tying the shorefast etc. This would be far more difficult in a survival suit. With regular foul weather gear with layers, you would have little protection from the cold water if immersed. Luckily I did not test this scenario out with the exposure suit.
I found the exposure suit quite handy in many ways. It hung in the companionway and was easy and fast to put on when I needed to get on deck in a hurry. Even for casual inspections while at anchor, I could pull the exposure suit on quickly over underwear and T shirt and be quite comfortable working the anchor or checking things out for a while. On a number of day sails in Greenland, I wore the exposure suit and felt like I could work the boat effectively in it. In some ways it was easier than my foul wx gear and layers, but generally I preferred those to the exposure suit. The exposure suit is quite bulky and its flotation/insulation does not compress in the slightest, so storage on a small boat like mine was/is an issue.
Come back with thoughts/questions/comments,
My best, Dick Stevenson, s/v Alchemy
By Dick - 29 Nov 2018

Hi Daria,
One more thought: if cruising in cold water, the gear which allows one to stay in the water for at least 10-15 minutes (the time to cut away an ugly fused prop wrap with multiple dives), for me, is essential safety gear. Again, for me, if the water is below 10-12C/50-55F degrees a drysuit is preferable over wet suits. Having a hookah of some sort (I carry a dive tank with a 40 foot dive hose-tank stays on deck) makes any underwater work far far easier.
My best, Dick
By DariaBlackwell - 1 Dec 2018

Again, very valuable information. We have wet suits aboard and we do sail in colder waters. I tend to handle cold much better than Alex. I think I've just found the Christmas present answer for Alex. ;-) Many thanks.
We have a hookah and have found it quite valuable for cleaning the bottom. Fortunately, having a long keel and a skeg hung prop plus a cutter blade on the shaft has fortunately kept our prop free from fouling so far. BTW that's very clever to have a long hose for a dive tank that stays on board. I stopped diving because the gear was just so heavy and cumbersome.
edited by DariaBlackwell on 12/1/2018
By Dick - 1 Dec 2018

Hi Daria,
Agree, dive gear is big, heavy and a royal pain—until you get in the water. I carry my BC vest only for dealing with the possibility of a foul anchor or some other need to go deeper than my makeshift hookah allows.
I wish I could say that you have chosen an inexpensive present, but I am unable to do so. They are not a minor purchase, but, with some care, they will last a long time. Mine is an NRS Crux drysuit and it checks all the boxes for me. I found a Whites Thermal Fusion (one piece very thick fleece essentially) in a going-out-of-business dive shop that allows me to stay for long periods in very cold water. I love it but admit that it might be over-kill. Think fleece for tops and bottoms as undergarments as you want uncompressible thickness. Long underwear is generally too thin. Plan on extra weights as the thicker the undergarments, the more weight you will need to achieve neutral buoyancy and certainly more weight than wetsuits demand.
My best, Dick Stevenson, s/v Alchem