krawlings
Contributor
I did a 45 minute dive with close to 3 gal of water in my suit (that is how much pored out after I took it off)I had a zipper seam come apart .
Loss of Buoyancy from Flooded Drysuit
- Thread starter kafkaland
- Start date
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In the case of a catastrophic flood inside your dry suit, you can always release your weights (belt and/or BCD incorporated). This will give you a lot of buoyancy to go to the surface and be light enough to climb the boat stairs.
the_dragon_no1
Contributor
Seems no one realy knows, but if there was a "catastrophic failure" to the suit IN the water... would you realy be more negative IN the water ? (Not on surface or on land....)
I have heard stories about divers retrieving other diver with this problem... they got to negative.... but..... is it realy a fact or just a myth :??
I have heard stories about divers retrieving other diver with this problem... they got to negative.... but..... is it realy a fact or just a myth :??
PfcAJ
Contributor
I must not have been clear enough before.
If your suit floods, the WORST CASE is that it loses all its *positive* buoyancy. The suit itself will not become negative since water is neutral in water.
Since you could potentially lose all that positive buoyancy, your BC will need to have enough lift to support your kit. Humans are almost always neutral to positive (a few of you super thin types or muscle guys might be a few lbs negative but its minor). Ergo, if your BC can support your full tanks WITHOUT a diver in it, you're good. In reality, a total loss of all positive buoyancy in a drysuit is a rare beast.
This brings us to the concept of a balanced rig:
#1 Enough weight to stay at ~15ft with an empty tank
#2 Light enough to swim up with a full tank and empty BC. If you cannot do this, you need some sort of solution (ditchabe weight, perhaps) that allows you to do this without violating #1. This might mean that your tank and suit combo is inappropriate.
# Enough BC lift to float your rig without you in it. More than this is not better.
If your suit floods, the WORST CASE is that it loses all its *positive* buoyancy. The suit itself will not become negative since water is neutral in water.
Since you could potentially lose all that positive buoyancy, your BC will need to have enough lift to support your kit. Humans are almost always neutral to positive (a few of you super thin types or muscle guys might be a few lbs negative but its minor). Ergo, if your BC can support your full tanks WITHOUT a diver in it, you're good. In reality, a total loss of all positive buoyancy in a drysuit is a rare beast.
This brings us to the concept of a balanced rig:
#1 Enough weight to stay at ~15ft with an empty tank
#2 Light enough to swim up with a full tank and empty BC. If you cannot do this, you need some sort of solution (ditchabe weight, perhaps) that allows you to do this without violating #1. This might mean that your tank and suit combo is inappropriate.
# Enough BC lift to float your rig without you in it. More than this is not better.
Buoy_A
Contributor
(I've added the bold to the font to highlight the statement - Buoy_A)
Well water gushing into a drysuit won't make it negative. However, the way you've phrased it "more negative", then yes, it will be "more negative" than before the water gushed in. In other words, it was previously positively buoyant, and now that water has gushed in it is neutrally buoyant. So it is not "negative", but it is more negative than it was before the water entered. I think the proper, less confusing phrasing should be "less positive" rather than "more negative".
Put your self in a pool, with the ds on (no gear) and find out how much weight you will need to get you down. Need to do this for each set of undies. that weight is what you will have to deal with if you flood your suit. my tls350 with 300 gr undies needs 38#. Same suit with 100g undies needs 19#. also with a large amount of weight on the hips you may need a wing that has more lift at the hips than the shoulders. you can manipulate this say with a DSS back plate with the added weight plates bolted on the plate. If iI had to guess you will need around a 60# wing for heavy undies. 50# with lighter undies. dont forget to comp for salt water. numbers will vary depending on how you are configured as far as ditchable weight goes. BTW I cant use the same wing with both sets of undies.
I can't give you a number, but I can tell you a story. I had a dry suit complete flood about thirty minutes from shore at our local underwater park. I had to add quite a bit of air to my wing to stay neutral underwater, and swimming with legs full of seawater wasn't at all fun. But it was all manageable until we surfaced. Then, the wing had trouble getting my whole head out of the water. I assume this is because I had no buoyancy at all from the suit, AND the wing was trying to lift some of the sodden undergarment out of the water. I tend to like to float with my whole head out, and the best I could do was water at my chin. This was without dropping any weights, and with half-empty tanks.
DaleC
Contributor
Unless you are diving a shell drysuit with minimal undergarments you will lose buoyancy from a full flood, you will not be neutral.
Even if you dive with a squeeze on, your body mass, the various creases in the suit and the thickness of the garment full of airspace, all create displacement. That displacement equals your buoyancy (plus whatever your rig is doing).
When you flood, water fills the air space in the creases and your clothing, and that is the amount of buoyancy you will lose.
For some people this could be a little or a lot. Look at what you wear and how much air it traps. I know people who wear two sets of wool socks, fleece and a puffy vest. Add up the volume of all that air space, plus the volume of bubble they usually run in the suit and express it as water weight. That's how heavy one will be when fully flooded.
Here's an experiment:
Take all your undergarments;tops, bottoms and socks, and put them into a bucket. Push down (that's diving with a squeeze on) and mark the bucket as to how full it is.
Now weigh that bucket of garments on a scale (not much eh).
Take out the garments and fill the bucket with water to the fill line.
Weigh the water on the scale (more eh).
Subtract the weight of the garments from the weight of the water and what you are left with: That's how heavy you will become (plus the volume of creases in the suit, boot space, and the bubble you weight yourself to ordinarily run with that will also fill with water).
As someone who solo dives in cold, remote settings I think about this a lot. Besides a medical event (stroke, heart attack etc...), a full flood would probably be the worst thing that could happen to me when you consider shock, hypothermia and exhaustion. Shore diving would be problematic enough but from a boat it would be very difficult to manage. Having an exit strategy is an important part of my pre-dive planning.
Even if you dive with a squeeze on, your body mass, the various creases in the suit and the thickness of the garment full of airspace, all create displacement. That displacement equals your buoyancy (plus whatever your rig is doing).
When you flood, water fills the air space in the creases and your clothing, and that is the amount of buoyancy you will lose.
For some people this could be a little or a lot. Look at what you wear and how much air it traps. I know people who wear two sets of wool socks, fleece and a puffy vest. Add up the volume of all that air space, plus the volume of bubble they usually run in the suit and express it as water weight. That's how heavy one will be when fully flooded.
Here's an experiment:
Take all your undergarments;tops, bottoms and socks, and put them into a bucket. Push down (that's diving with a squeeze on) and mark the bucket as to how full it is.
Now weigh that bucket of garments on a scale (not much eh).
Take out the garments and fill the bucket with water to the fill line.
Weigh the water on the scale (more eh).
Subtract the weight of the garments from the weight of the water and what you are left with: That's how heavy you will become (plus the volume of creases in the suit, boot space, and the bubble you weight yourself to ordinarily run with that will also fill with water).
As someone who solo dives in cold, remote settings I think about this a lot. Besides a medical event (stroke, heart attack etc...), a full flood would probably be the worst thing that could happen to me when you consider shock, hypothermia and exhaustion. Shore diving would be problematic enough but from a boat it would be very difficult to manage. Having an exit strategy is an important part of my pre-dive planning.
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PfcAJ
Contributor
n/m...
Looking at the last two posts I feel justified about concern. I wear a Weezle Extreeme+ and moving that when wet would be like wearing a thick, soaking wet quilt. I've had remarkably large amounts of water get in just from a loose neck seal in a very unfortunate position. It has made me wonder: if the suit were actually to rip or zipper completely fail, I wonder how much water would collect in the suit.
I think I'll just have to try it in the pool and see. Of course I'm also more than happy if someone else wants to run out and make the video
BTW Like many others, I don't carry ditchable weight.
I think I'll just have to try it in the pool and see. Of course I'm also more than happy if someone else wants to run out and make the video
BTW Like many others, I don't carry ditchable weight.
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