Discussion in 'Paddling Safety' started by nootka, Apr 28, 2019.
It seems to me that they are missing the point.
I agree that it will not 'sink' you if you get water in the suit....just as water in a backpack hydration bladder (tributary) will not 'sink' me or reduce the effectiveness of my PFD, while I'm swimming.
But, will it impede a rescue - assisted or self-rescue?
As soon as you try to lift that water 'into the air', it's not a neutral buoyancy situation any more - water is heavier than air!! Try to lift a swimmer into a Zodiac with a lot of water in the suit, or try to get into your boat again during an assisted rescue....
It's quite easy to float if you don't 'burp' your suit and keep a nice big air 'balloon' around your shoulders. If she had gotten that air into the legs of the suit she could have been in trouble (legs up, torso down..).
Fill up the legs of the suit with water- as she did in the first 'test', and see how well you can kick your legs to get them to the surface. That water has mass and inertia. Even with a dry suit without a leak, there can be enough water in the legs (most suits have 'inner and outer' layers up to the knee to go over boots) to make it hard to get one's legs to the surface by kicking. I've seen a lot of scramble/cowboy rescues fail because the swimmer couldn't get their body horizontal so they could 'swim over' the stern of the kayak. Baggy leg suits make this worse.
The idea that it's normal to swim to shore and walk out of the water seems a bit unrealistic.
Is the ocean really 4C in Vancouver?
Obviously you won't sink completely, because the water that floods your suit the is same water with the same density as what you're swimming in. But you will lose the additional buoyancy of a dry drysuit (but you're wearing your PFD right? Right?) Hypothermia could also be a problem. Reboarding your boat might be a challenge as you try to lift that dense, heavy water into the light, unsupportive air. In a real emergency, you might have to use the knife on your PFD to create drainage holes on the lower legs.
isn't the sink part of the test negated because she's wearing a wetsuit [lots of bouyancy] underneath?
oh oh, just looked at the 1st part,the 2nd part concluding that all the extra weight impeding motion seems like a no brainer - how would anyone like to deal with an unpredictable free surface effect while they're gaining 50 lbs or so?
As far as air ballooning in drysuitlegs, I'd think that's great 'cause then I'd only have to swim half as hard - if I had a kayak and no roll, it'd be a great outrigger while my upper body rested on the yak.
my old Oceanography of BC Coast book [the best book in the world, circa 1990] mentions temps being 8 - 15 deg C [if I recall correctly].
Interesting video. Thanks for posting.
I do find people who believe that a leaky dry suit (or suspenders for the fishing crowd) would cause someone in the water to sink to the bottom. A little bit of physics knowledge would tell you that water is not heavier than water, so would not cause you to sink. But it was good to see their experience.
It was good that they redid the test without a wet suit on, as a wet suit does provide flotation. And the last test with the guy actively trying to fill the dry suit was also good. Interesting that the dry suit doesn't balloon out to fill more, but stays pretty tight to your body, especially if you have burped it. Kind of expected this, but as good to see an example.
I did cringe when the showed the water temperature. Was that Lake Ontario off of Toronto?
Was also good to see the impact water in the dry suit had as they walked out of the water. The fact that they could at all was informative. Yes, water in the dry suit would make rescues harder, but it doesn't seem like the suits would Michelin Man out and fill with hundreds of pounds of water.
A complete concidence: I've been reading some back issues of the Victorian (Australia) Sea Kayak Club newsletter, and I came across an article ('Killer Cags' by Sarah Black) that might be pertinent to this thread.
The whole article is well worth a read; I'll paste part below.
One person I used to paddle with would not burp his drysuit. When he tried a wet exit, he had a lot of difficulty getting out of the kayak because his flotation in the upside down boat pressed him in. I suggested burping but because of "you're not the boss of me" attitude, he refused to do it.
Well, an alternative view is that he would have extra insulation and extra floatation. Maybe he would float sideways in a 'wet exit' and have an easier time?
I mean, I wonder if there was a way of thinking to make it advantageous: I've often thought that drysuits should all have blowup tubes so that one could achieve that extra floatation or insulation in dire circumstances.
It's sort of an "over pizza and beer" discussion. I mean extra floatation can actually get in the way. And each additional "complication" - blowup tubes and such - is an additional point of failure. I like to think in terms of function. It's the PFD's job to keep me afloat. It's the drysuit's job to keep me dry (it's my base layer's job to keep me warm). If there was a higher potential of a closed cell foam pfd to not provide "float", then having the drysuit provide floatation via tubes and chambers would be a "backup". But I'd go for simplicity - if only because the cost of a drysuit is high enough as it is.
On a couple of occasions when I had quite a bit of air in the suit and was 'vertical' in the water beside the boat (rescue demo/practice), I heard air escaping past the neck gasket. (Usually I reach a finger inside the neck gasket to 'burp' the suit -easy when in the water, no contortions necessary....). This was with a gasket that was completely watertight for rolls, etc..
So perhaps it would be difficult to keep air inside the suit if it was 'pumped up'?
If I was separated from my boat in a dry suit and needed to float a wile, I wold puff the dry suit up some for added flotation (and likely insulation). You pull the gasket up over your mouth and breathe in with your nose and out into the body with your mouth. For fun, I have done this and floated around. If you think you might do similar in emergency situation, might be worth playing with this before a real emergency pops up. The air does move around to highest pint, which may not be in a spot that you want to be your highest point.
One of my puffed up drysuit playing around sessions showed up very briefly in a video (time 3:47):
So perhaps it would be difficult to keep air inside the suit if it was 'pumped up'
So what if it was 'designed' where and how they could be blown up to minimize balooning? [but in dire situations wouldn't any balooning almost be welcome because of the additional benefits?]
in diveing we used ankle weights so we would not go upside down in a dry suit
i can think of situations where haveing your feet substaintialy more boyant than your head would be sub optimal
Some diver's drysuits have a tube to inflate/deflate as needed, OceanRodeo have that on some of their Drysuits designed for SARTECH and military use, those might be a bit heavy for Kayaking tho..
My brother borrowed a faulty bouyancy compensator from a friend, which overinflated the legs of his drysuit. Because there was quite a bit of extra room in the legs, he was repeatedly inverted, and nearly drowned at the surface. I think he had to cut a hole in the suit.
come on guys: we're talking about a kayaker situation where the kayaker is typically wearing a pfd and obviously a drysuit with inner insulation which obviously has some upper buoyancy as well . . .
so the setup is that the guy is floating parallel with the surface of the water. Did the two examples drop their wt belts?
this is great for self rescue getting on the boat if there's no roll [parallel to the surface, parallel to the decktop, and outrigger for stability], but obviously lousy for inserting into the yak - but if the issue is straight survival, and assuming parallel to the surface [in a kayaker and no boat situation] I would think its better thermally and better floatationally than if fully burped.
Now I haven't tried it . . . so am I being little optimistic here?
Ok, so if I am, what about designing a ltwt drysuit with double panels [all vapour permeable] in some more upper areas that are linked/linkable [say oneway valves so no massive failures] to a blow tube - would that be an interesting kayak drysuit? Themally and floatationally?
Michelin man [floats] again!
On using a paddler's GoreTex drysuit as a survival suit: the USCG variant used for their SAR swimmers has a very heavy duty fabric, probably not breathable, and even so, rips are common. Likewise, dive quality dry suits are made of obnoxiously thick/durable fabrics.
It was a dive suit that trapped my brother upsidedown when the B/C went into overdrive. Even with the weight belt gone, his feet had most of the excess air, and he was upside down. The air tank harness and other gear kept the space over his chest, etc, relatively uninflated. Other details pretty hazy.
Separate names with a comma.