Bcd filled with water

[Allen-1]

This is true,

but

many newer divers do not fully understand that air wants to go up, so if there is not a whole lot of air in the BCD, it will only be at the highest point in the bladder, and it is possible that the highest point will not be the point from which the diver is trying to dump the air. You see this frequently with divers pressing the dump button on the inflater hose while it is down by their chests and wondering why air isn't leaving the BCD.

My instructor taught me to bring my right shoulder up to the highest point possible before using that dump valve. That way the air "bubbled up" to the valve. He also emphasized releasing the valve quickly, as leaving it open once the air was gone wasn't doing anything other than potentially letting air water in. Using the lower dump valve while vertical, (head up), is pretty much guaranteed to let water in while not releasing any air.

Edited to correct "air" to "water". Need to proofread better before hitting post.

 

[DanBMW]

Do not detach your inflator hose unless you know ahead of time that it will be easy to reattach. Some like Scuba Pro are difficult and not something I'd recommend. Just know ahead of time.

 

[grantmac]

Don't need a BCD in swim trunks with a single tank.
Dive cold water and everything changes.

 

[DanBMW]

Don't need a BCD in swim trunks with a single tank.
Dive cold water and everything changes.

They can come in handy for a new diver as a way to hold their bottle of air and diver safety tools. Most of the time, more comfortable than not.

 

[The Chairman]

Don't need a BCD in swim trunks with a single tank.
Dive cold water and everything changes.

65F is my lower limit!

 

[OMyMyOHellYes]

65F is my lower limit!

 

[John Bantin]

The human body is incompressible. It displaces the same amount of water at any depth. The ABLJ (and BC) was introduced to counteract the changing buoyancy of the wetsuit as it gets compressed at depth, and the mass of air in the tank depletes as it gets used. What a shame so few divers are taught how to dive properly weighted and to exhale to leave the surface, For example, I can change my buoyancy by 6kg (13.2 lbs) on lung volume.

 

[iain/hsm]

The human body is incompressible. It displaces the same amount of water at any depth. The ABLJ (and BC) was introduced to counteract the changing buoyancy

That's utter nonsense John. I'm displacing way more water at any depth now a days
So much they think its spring neaps early. Besides what the heck is an ABLJ?
some kind of gastric band to counteract the changing buoyancy.
Just glad you're still kicking. Iain M

 

[johndiver999]

Physiology, Tidal Volume - StatPearls - NCBI Bookshelf

Tidal volume seems smaller than people claim here. 500 ml of volume is a little over 1 lb

 

[34109411]

Hi, I'm new to diving. Have 20 dives. I just purchased an Oceanic Hera BCD. When I returned after 2 dives I heard water moving around in tge bladder. I pulled the lower dump cord and there was a gush of water ( alot of water) that came out. Not a small trickle but alot water. I know water can get into the bladder but this seemed like an aweful lot of water. Is this normal?

no worries take out the water at the end of the dive. purge it.