I don’t have much experience with drysuits as I live in the south, but have worn an old Stohlquist pod from time to time, in the winter, and have a new Kokatat which I have only worn paddling once. In any case, I’m wondering if a PFD is partly redundant as even when you try to get most of the air out, you have some amount of extra buoyancy with the air that is invariably inside your drysuit and, in the water, if needed, you could add plenty more air to your drysuit (by putting neck gasket over mouth and exhaling). If so, I can imagine wearing an inflatable PFD with the drysuit to keep the bulk down. On the other hand, I seem to remember from reading about drysuit diving, that you can’t control very well where the air ends up and if you end up with your head below your legs, the air can rapidly move there and then sort of anchor you in a feet up position, so maybe a foam PFD is more important than ever. Any thoughts? Thanks.
You want to burp your drysuit to release the air inside the suit and rely on your pfd to float you.
If you have a lot of air trapped in your dry suit you will end up like the Michelin Man and it will hinder your mobility. Air inside the suit will provide some buoyancy but I sure wouldn’t consider a PFD to be redundant.
One of the instructors in a course I took was messing around one evening at the water’s edge. We were all in dry suits still from the day’s paddling. He pulled the neck gasket up over his mouth and proceeded to inflate his suit to look, as @pblanc says, like the Michelin Man. He fell backward into the water and started floating away like a blow-up pool toy in the wind. When he began to plead for assistance, we all thought he was playing around still. It wasn’t until he called one of the other instructors by name in a rather urgent tone to come help him that it was quickly realized he was having trouble.
Turns out he had put so much air into his suit that when he laid back on the water he couldn’t get his arms back to the neck gasket to release the air. He was floating away from all of us without any control whatsoever.
So, just like a drysuit is not intended to keep you warm, it is also not intended to keep you afloat. Now, a “floater suit” or “survival suit” is made to do both, from what I know of them. Very different than a dry suit though.
I’ve found that even after I burp out most of the excess air within a dry suit, paddling at a high level of exertion will cause the suit to balloon out again as the remaining air gets warmer and expands, leading to the need for burping out the excess again. What this tells me is that the opposite will happen when dunked in cold water. You can imagine that with most of the air volume expelled when the inside of the suit is very warm, being dunked in cold water could cause a drastic reduction in the volume of contained air and very little volume being present for flotation.
You are also correct that whatever air is present will simply flow away from any areas on which pressure is exerted from the outside by water, and if you are floating horizontally at the surface, the air could easily end up all being within the dry suit’s legs with your upper body sagging down beneath the surface. Recovering from that would be problematic even under the best of situations, I’m sure, and I sure wouldn’t want to deal with that under the worst of situations.
I would not count on being able to exhale into the suit to add air AFTER you are already in the drink. You would need the neck gasket to fully seal while you were doing that, and in that position, it probably wouldn’t seal at all. Any loss of neck-gasket sealing would result in instant loss of all excess air in the suit, since water would be exerting pressure from the outside. You’d need that seal to be maintained even when transferring the gasket back to its proper location, and that, I’m sure, is impossible. Besides, you will have other worries, like holding onto your boat and paddle, waves that might be tossing you around (or turbulence, for whitewater boaters), and your hands might be rapidly going numb, all in all, not a good time to be messing around with your neck gasket.
I used to sometimes wear my PFD inside the dry suit, with the idea that some extra air for upper-body buoyancy would naturally be trapped there since the suit could not be compressed fully against the body to fill all the open spaces within the PFD itself, but that seemed like more trouble than it was worth, especially since I also wore a large shirt over the PFD to protect the delicate interior of the dry suit from scuffing, and it simply made the dry suit harder to put on. Now, I wear my PFD on the outside like everyone else does.
Think of gaskets working better with water pressure than without to seal.
"the opposite will happen when dunked in cold water. You can imagine that with most of the air volume expelled when the inside of the suit is very warm, being dunked in cold water could cause a drastic reduction in the volume of contained air "
Just ask Tom Brady.
Burp the drysuit and wear your PFD. I don’t do it, but some people will go in the water to push all the air out. As stated earlier, air in the drysuit can effect your mobility, and make it more difficult to swim if the air ends up down at your feet.
Yes - burp the suit. And sometimes you have to do it after paddling a while. I ended up in a suit that had gained air without my realizing it on a cold water/warmer air day and decided to pop a quick roll before getting out. Once upside down I realized the suit had a lot of air in it, I actually had to push the boat off of me to get out from under it.
Not fun.
Keep some air in suit for insulation
@PaddleDog - I have yet to find that the suit doesn’t build up some air as you paddle, regardless of temperatures. So leaving air in is not necessary, it’ll usually happen by itself.
So if you purge all the air by walking in the water and you fall in the water you won’t have any insulation from air. Not what I would like in cold water. I squat and lean forward and enough is out. Neck gasket can always relieve any extra air later.
@PaddleDog52 said:
So if you purge all the air by walking in the water and you fall in the water you won’t have any insulation from air. Not what I would like in cold water. I squat and lean forward and enough is out. Neck gasket can always relieve any extra air later.
When you are floating in the water, the water pressure will force all the air to the very top of your suit (with the very top being at your feet or at your shoulders depending on your position in the water). So on most of your body you will not have any insulation effect from the air anyway, unless you have a lot of air in the suit.
I prefer to rely on insulation from clothing under the drysuit instead.
I dress with underlayers sufficient to handle getting wet, since as above at some point the area under the PFD that can’t hold air anyway could get chilly. That has been in temps down to 34 degrees water and 20 degrees air, though I am more of a warmer weather paddler as I get older. I believe that qualifies as cold conditions…
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I burp it by squatting in the water first and opening the neck gasket slightly.
Feeling the drysuit wrapped against my underlayers tells me the suit is now burped. As celia stated, after a while, the suit does not stay “shrink wrapped” and might need another burping. This can be done while sitting in the kayak, though not as thoroughly.
The suit depends on underclothes for insulation much more than air. Otherwise, it would be a Michelin Man suit. Not good for mobility.
To address the original question, my drysuit floats me even if I don’t wear a PFD. So does a thick wetsuit (full length limbs). Whether the amount of buoyancy suffices if being tossed in waves is another question. We don’t get to opt out of having the PFD readily available anyway. Oddly, windsurfers ARE exempt from PFD requirements as long as they are wearing full wetsuits.
The inflatable PFD is allowed, but does it put YOUR mind at ease to wear that instead of a conventional foam one?
@Sparky961 said:
One of the instructors in a course I took was messing around one evening at the water’s edge. We were all in dry suits still from the day’s paddling. He pulled the neck gasket up over his mouth and proceeded to inflate his suit to look, as @pblanc says, like the Michelin Man. He fell backward into the water and started floating away like a blow-up pool toy in the wind. When he began to plead for assistance, we all thought he was playing around still. It wasn’t until he called one of the other instructors by name in a rather urgent tone to come help him that it was quickly realized he was having trouble.Turns out he had put so much air into his suit that when he laid back on the water he couldn’t get his arms back to the neck gasket to release the air. He was floating away from all of us without any control whatsoever.
So, just like a drysuit is not intended to keep you warm, it is also not intended to keep you afloat. Now, a “floater suit” or “survival suit” is made to do both, from what I know of them. Very different than a dry suit though.
Did he say, “Watch THIS!” before going puff?
That is the funniest story I have ever read about paddling mishaps. He probably avoids inflatable kayaks like the plague! They seem to have zero directional control in wind.
I have all the under layers also and go out in 35" water and air. Still rather have some air like a thermos. I see people walk in the water and look like they were vacuum packed which is not for me.
@pikabike said:
Did he say, “Watch THIS!” before going puff?That is the funniest story I have ever read about paddling mishaps. He probably avoids inflatable kayaks like the plague! They seem to have zero directional control in wind.
Good question. I think the big splash was enough to attract the attention he was looking for. He was quite the card, but also certainly knew his stuff and when to be serious as well.
While it’s a funny example of “improper” dry suit usage, it’s a much better parable to illustrate why one should consider the ramifications of their actions prior to undertaking them. Anyone not guilty of finding that one out the hard way at one point or another has been living under a rock.
@PaddleDog52 said:
I have all the under layers also and go out in 35" water and air. Still rather have some air like a thermos. I see people walk in the water and look like they were vacuum packed which is not for me.
I’ll be the smartass to point out that Thermos brand containers are actually vacuum flasks. Air is evacuated from a chamber surrounding the hot or cold interior chamber. They minimize heat transfer by controlling: radiation, convection and conduction.
http://home.howstuffworks.com/thermos2.htm
Air is a reasonable insulator though. You just have to keep it from moving around, which is what foam, down, clothing, and many other insulating materials do. I like “polar” fleece under a dry suit when the water is very cold because even with the water pressure compressing it slightly it still maintains some loft, and thus some insulating value. Even when damp, it still insulates - but obviously not as well as when it’s dry.
If I’m spending a lot of time in near freezing water I’ll wear a thin wicking thermal layer plus TWO layers of polar fleece. This is enough that I’d readily overheat above water, even in below freezing air. It really starts to limit my mobility, but there’s enough loft (insulation) that I can be in the water almost indefinitely. It’s really all the air that’s keeping me warm, just that the polar fleece keeps it from moving around.