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give me convenience
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Discussion Starter #1
Here is a question which is puzzling me, sorry if it has been done before:

If you are neutral and you add something that is positive e.g. full dsmb you will become positive.

If you are neutral and you add something that is negative e.g. steel stage you will become negative.

If you are neutral and you add something that is neutral then surely you should remain neutral.

Seawater is neutral. So why do you lose bouyancy if you flood your drysuit? :confused:
 

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Nigel Hewitt
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7,142 Posts
Seawater is neutral. So why do you lose buoyancy if you flood your drysuit? :confused:
Sadly if you flood your drysuit you let all that nice warm, buoyant air out and replace it with cold neutral seawater.

Net result is two big negatives.

Basically a flooded drysuit does not need so much lead on your belt. A fully flooded drysuit, very difficult to accomplish, is virtually the same as just wearing your swimmers. If you have a good hydrophobic undersuit it traps air and you don't actually loose much buoyancy so you don't notice it much until you try to climb the ladder with umpteen kilos of seawater in your legs.
 
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iGeek therefore iTrek
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3,253 Posts
Plastic bags float, plastic bags filled with sea water float - a flooded dry suit will stay neutral, providing you are using the wing / bcd for buoyancy
 

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Registered
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It is a loss of positive bouyancy (the air in the suit), not an addition of negative.

The effect is that you now need to add more positive bouyancy elsewhere (more air in your BCD for example) to replace the lost air in your suit and become neutral again.

If you were borderline with your BCD capacity you could struggle to keep your head above water on the surface, for example, and this is the point that ditchable weight shows its value.
 

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Slightly used member
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211 Posts
.

You might think that you have no air in your suit. But the
majority of dry suits are designed to have trapped air inside
to insulate you against the cold. Evan an expensive thinsulate
undersuit is useless if saturated in water.
So no mater how little you think you have air in your suit
there is air in there and to loose that air makes you less bouyant.


Cheers taz


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14-9-09
Joined
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3,169 Posts
.

You might think that you have no air in your suit. But the
majority of dry suits are designed to have trapped air inside
to insulate you against the cold. Evan an expensive thinsulate
undersuit is useless if saturated in water.
So no mater how little you think you have air in your suit
there is air in there and to loose that air makes you less bouyant.


Cheers taz


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Well, that just about sums up the summing-up of all the sums :confused:... I wish I'd written it first :rolleyes:

Broke:redface:
 
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