Drysuit Floods
Steve
I wanted to plan my worse care scenario if I ever had a drysuit flood being
new with drysuit about 70 dives. I asked on the techlist and it was cross
posted to rec.scuba, my question was. How much buoyancy would I loose if a
trilam TLS350 with thinsulate undergarments flooded?
Last Saturday on my third and final dive of the day at Catalina I noticed a
slow leak at the neck seal and thought this was a perfect opportunity to let
it flood and see. The water was 55 degrees which isn't that cold but after
the leak had spread down to my knees I thought it best to get out of the
water. Besides I was loosing buoyancy and had to keep pumping up the BC. I
need around 20 pounds to make my stop at the end of a dive because of the
buoyancy of the drysuit with undergarments. I can report to you that the
water was displacing the air that is trapped in the undergarments and I
would estimate that I would loose all 20 pounds of buoynacy had I let it
completely fill with water. Some posters gave me correct info some didn't.
Steve
Ben Bradlee
buoyancy you have trapped inside. It may be 20 pounds - it maybe more or
less depending on other factors. I'm not sure there is one correct answer.
As for your worst case scenario, there are a lot worse things than flooding
a drysuit.
"Steve" <sfke...@earthlink.net> wrote in message
news:B8577887.1671E%sfke...@earthlink.net...
Jason O'Rourke
>posted to rec.scuba, my question was. How much buoyancy would I loose if a
>trilam TLS350 with thinsulate undergarments flooded?
>water. Besides I was loosing buoyancy and had to keep pumping up the BC. I
>need around 20 pounds to make my stop at the end of a dive because of the
>buoyancy of the drysuit with undergarments. I can report to you that the
>water was displacing the air that is trapped in the undergarments and I
>would estimate that I would loose all 20 pounds of buoynacy had I let it
>completely fill with water. Some posters gave me correct info some didn't.
Steve, I'm not quite sure how you reached that conclusion. Certainly
some indications, but conclusive?
Obviously the air will be displaced by water. The question is how much
bouyancy is provided by the thinsulate. As long as it still occupies
volume, it will still provide some lift. For those that use a large air
pocket and weight to match, the loss would be greater. At the end of a dive
with an empty tank, I don't feel much air is left in my suit. It would be
best for me to flood and see, but I'm feeling a bit lazy.
When I first got my drysuit, I did one dive in Monterey with an Aeroskin
(non neoprene) and needed 16. With the Mobby thinsulate suit, it became
24-25. That difference might be close to the value it provides.
--
Jason O'Rourke www.jor.com
Steve
j...@CSUA.Berkeley.EDU wrote on 1/1/02 6:36 PM:
> It would be best for me to flood and see, but I'm feeling a bit lazy.
It would be best to know, like you I was too lazy so I asked. I got the
wrong answer from some big names. Check the thread, August 2001.
> The question is how much bouyancy is provided by the thinsulate.
Very, very little if saturated. Sink it in the tub if your too lazy to go to
the ocean. It's no life preserver.
Steve
Steve
kjoh...@splinteredrocktelbiteme.net wrote on 1/1/02 3:25 PM:
> I guess I don't see your point. You flood a drysuit and you lose whatever
> buoyancy you have trapped inside.
You were one of the few who was right. Kudos.
Steve
Jason O'Rourke
>> The question is how much bouyancy is provided by the thinsulate.
>
>Very, very little if saturated. Sink it in the tub if your too lazy to go to
>the ocean. It's no life preserver.
ah, that might work well. It could use a wash anyhow.
Aviatrr
>new with drysuit about 70 dives.
I don't dive a dry suit(yet!), so I couldn't say what would happen one way or
the other - but I suggest carrying a lift bag if you feel that you may not be
able to obtain positive buoyancy with a flooded drysuit and all ditchable
weight dropped......however unlikely that may be.. Is all of your weight
ditchable?
Mike
Rob Turner
"Aviatrr" <avi...@aol.com> schreef in bericht
news:20020102005549...@mb-cf.aol.com...
> >I wanted to plan my worse care scenario if I ever had a drysuit flood
being
> >new with drysuit about 70 dives.
I didn't get the original so I'll jump in here.
If your suit were to totally flood (an extremely unlikely event), two things
would happen. First, you'd lose quite a bit of buoyancy and start to sink.
The main first priority would, therefore be to stop the descent and get
neutral again. The amount of buoyancy that you'd lose would depend on the
type of dry suit and the amount of air you had in it at the time. It could
be quite a lot.
Unless you are hoplessly overweight, most modern BCD's will have enough lift
to get you back to the surface so you don't need to worry about not being
able to ascend. If your BCD won't do it by it'self, start dumping weight
and you'll go up. Don't dump too much at one time because you'd like to
keep the ascent somewhat controlled if at all possible.
The second thing that would happen is that you'll start getting undercooled
very quickly. You're probably not diving dry for nothing so hypothermia is
acutally a bigger danger than losing buoyancy if you ask me. You need to
get out of the water and dry ASAP to avoid freezing to death. In cold water
I would assume that you'd have about 10 minutes to get to safety, maybe a
little longer if the water isn't circulating too badly through the suit.
Cheers,
R..
Iain Smith
> need around 20 pounds to make my stop at the end of a dive because of the
> buoyancy of the drysuit with undergarments. I can report to you that the
> water was displacing the air that is trapped in the undergarments and I
> would estimate that I would loose all 20 pounds of buoynacy had I let it
> completely fill with water.
Steve,
Am I right in thinking that you're still diving on the buoyancy of the suit?
(ISTR that we had a short discussion about whether one could lose the BC
altogether - I think your post above suggests an excellent reason why not!).
It would be interesting to see the comparative buoyancy loss in a diver who
dives on the wing only - I'm afraid that I won't be volunteering - due to
dive on Saturday and it's going to be about 40F...I'm not that hardy a soul!
Of course, if it happens by accident, I'll be sure to post the results once
they chip me out of my icecube!
Iain
Slimmmy150
my class and you would have to flood it on pourpose after you had a simulated
run away inlet valve. I hope you do try to see how you would handel that along
witht he differant methods to get air back down if it gets into your leggs to
start floating you up.
Steve
iainm...@btinternet.com wrote on 1/2/02 2:43 AM:
>> Besides I was loosing buoyancy and had to keep pumping up the BC. I
>> need around 20 pounds to make my stop at the end of a dive because of the
>> buoyancy of the drysuit with undergarments. I can report to you that the
>> water was displacing the air that is trapped in the undergarments and I
>> would estimate that I would loose all 20 pounds of buoynacy had I let it
>> completely fill with water.
>
> Steve,
>
> Am I right in thinking that you're still diving on the buoyancy of the suit?
> (ISTR that we had a short discussion about whether one could lose the BC
> altogether - I think your post above suggests an excellent reason why not!).
> It would be interesting to see the comparative buoyancy loss in a diver who
> dives on the wing only -
I dive suit inflation to prevent painful squeezes only and the balance
necessary with buoyancy in the BC. Knowing this now, I wouldn't dive dry
trilam's without backup buoyancy.
Jason O'Rourke
>The second thing that would happen is that you'll start getting undercooled
>very quickly. You're probably not diving dry for nothing so hypothermia is
>acutally a bigger danger than losing buoyancy if you ask me. You need to
>get out of the water and dry ASAP to avoid freezing to death. In cold water
>I would assume that you'd have about 10 minutes to get to safety, maybe a
>little longer if the water isn't circulating too badly through the suit.
It may not be that bad, Rob. Many of us dive at the threshold where dry
suits become necessary - 8-13C is the typical temp range. I can swim over
a 1000m in 13C water wearing only speedos. I'm not in great shape afterwards,
but that's nearly 30 minutes and I'm still only hitting minor hypothermia.
In that temp, I think I've good for an hour. Dropping down to the 6-8
range, it drops considerably, but you are wearing thermals at least. They
should act as a bad wetsuit and trap a bit of heat.
Jammer Six
<sfke...@earthlink.net> wrote:
€I dive suit inflation to prevent painful squeezes only and the balance
€necessary with buoyancy in the BC. Knowing this now, I wouldn't dive dry
€trilam's without backup buoyancy.
Double bladders!
You need a set of wings with double bladders, Steve!
--
"C'mon, you sons of bitches, you want to live forever?"
-Sergeant Major Dan Daly
spd135
Steve, even though most mainstream agencies don't teach this yet, you
should use your BC / Wings, etc. for your bouyancy. By completely
purging the air in your drysuit, and using gaitors, (I use neoprene
knee wraps just below my knees) and using just enough gas to relieve
the squeeze, you will find drysuit diving easier and a lot less
taskloading. I use the gaitors below my knees to prevent air from
getting to my feet. Usually one foot gets the air and I am left off
balance. By entering the water to my knees the air is pushed up and I
then put my gaitors on. I then dive using my wings for inflation and
bouyancy. My Drysuit becomes the backup and there is less of a chance
of flooding it when there is little to no air in it. Unless there is
a seal that is not , well, sealed, or the suit gets torn, major
flooding is usually unlikely. The few times mine flooded is when air
was escaping on my ascent and water followed it back in. You will
find, if you try this method a few times, your diving will be less
complicated and more FUN. I hope this helps some. Mark
icediver
required? The one catastrophic flood I had was jumping into 45 F
degree water with my relief zipper wide open. Yeeeooowww! The
weight of the water inside my suit was so much that I could barely
climb back out. Plus my voice was three octaves higher for hours.
slimm...@aol.com (Slimmmy150) wrote in message news:<20020102081924...@mb-cb.aol.com>...
Joe R
> "Aviatrr" <avi...@aol.com> schreef in bericht
> news:20020102005549...@mb-cf.aol.com...
> > >I wanted to plan my worse care scenario if I ever had a drysuit flood
> being
> > >new with drysuit about 70 dives.
>
> I didn't get the original so I'll jump in here.
>
> If your suit were to totally flood (an extremely unlikely event), two things
> would happen. First, you'd lose quite a bit of buoyancy and start to sink.
> The main first priority would, therefore be to stop the descent and get
> neutral again. The amount of buoyancy that you'd lose would depend on the
> type of dry suit and the amount of air you had in it at the time. It could
> be quite a lot.
>
> Unless you are hoplessly overweight, most modern BCD's will have enough lift
> to get you back to the surface so you don't need to worry about not being
> able to ascend. If your BCD won't do it by it'self, start dumping weight
> and you'll go up. Don't dump too much at one time because you'd like to
> keep the ascent somewhat controlled if at all possible.
>
steel doubles don't need any additional lead... The best solution is
to be weighted correctly, if you are diving gear that is very negative
have some type of backup buoyancy whether it be a second bladder or a
lift bag.. better yet BOTH.. When diving doubles and stages I always
have a redundant bladder and TWO lift bags (when properly stowed they
don't take up any room) with me (2 reels also) they serve as an up
line if necessary, the second is in case the reel gets fouled while
shooting the bag, I still have another option...I haven't ever had a
problem but Murphy is always lurking around the corner.
Glawackus
>Obviously the air will be displaced by water. The question is how much
>bouyancy is provided by the thinsulate.
The followup makes it sound like you may be talking about buoyancy of the
flooded thinsulate, but I first thought the real question you were asking is
how much air is normally trapped by the thinsulate? If that's the case, I can't
say for thinsulate specifically, but vacuum packing fairly normal clothing
makes for a substantial reduction in volume. You could probably get a decent
approximation by putting the stuff in a ziploc bag and weighing it after
*gently* squeezing out the excess air, then filling it with water, gently
squeezing out excess water and weighing it again. If you should happen to
have a big enough graduated cylinder, you could measure the displacement in the
ziploc and out of the ziploc for an even more accurate result.
Steve
The above can be construed as personal opinion in the absence of a reasonable
belief that it was intended as a statement of fact. Or it might just be to
generate discussion.
Glawackus
>Knowing this now, I wouldn't dive dry
>trilam's without backup buoyancy.
What about a neoprene drysuit?
Vic
>Dropping down to the 6-8
>range, it drops considerably, but you are wearing thermals at least. They
>should act as a bad wetsuit and trap a bit of heat.
When I got my new Weezle, I was slightly miffed that, at the end of a day's
diving in a (cold) quarry, I was rather chilly.
It was only after I worked out that I'd spent 2 hours in 6C water in a flooded
membrane drysuit that I realised just how good it is...
Vic.