BC full or not - Split from overweight

[Walter]

It looks like we both used the precise figure of 0.0745 lbs per cu ft at 70F and sea level.

The approximation of 6 pounds per 80 cubic feet is close enough for practical purposes, which in turns works out nicely to about 1 pound per 500psi in an AL80.

Actually, I used 6/80, came up with 373 and rounded to 375. LOL!

 

[mikerault]

With my dual 80's, SS BP and drysuit I usually require about 14 pounds of lead in order to maintain a safety stop with 1000 PSI in the tanks at the end of a dive. This requires me to add a bit of air to the wing during entry to be slightly positive enough to be comfortable on the surface. During a boat entry I usually pop a little air into the wing just to make sure I am a little positive because most of the boats I have dove off of want to see you positive and give a OK signal before the dive starts. The only time I didn't pop a little in I nearly had a situation since the inflator host connection at the wing was loose (I had repositioned the hose to lay better and thought it was tight) and I couldn't fill the wing. I was able to stay up but it was a bit of a struggle.

So I vote for a bit of air in the BC or wing just to make sure things are working and sorted out before you find yourself on the express elevator to the abyss.

Mike

 

[shadragon]

Go in with your BC inflated or not, it is, in the end, your choice. I know I am usually a bit overweighted (couple of pounds or so).

If it was 20 extra pounds then you would be over-weighted. A couple of pounds negative (or whatever you needed to start with to be neutral at the end of your dive after your tank air was consumed) is proper weighting.

I am surprised there are not a few divers out there with salinity test kits. Then they can determine the salt water density value to 10 decimal places and use cheese grater type tools on the dock to shave off the three of four extra grams of unnecessary lead weight to compensate.

 

[TSandM]

I have no problem with jumping off the boat and immediately descending, if conditions require it. We did this in some of the current diving in Cozumel.

But my diving at home is almost always in flat water with very poor visibility, and making sure the team is close together and prepared to descend at the same moment is often critical. I suspect, as Soggy says, that I'd have enough air trapped in various places to be able to stay on the surface by swimming, but I'd simply rather not. Being relaxed and comfortable and not at all winded is a very good place to start a dive for me, and I can see no detriment whatsoever to having my wing inflated when I get in the water.

Maybe not until the overpressure valve pops, but I'd be one of those people with a full wing that you guys would be regarding with suspicion.

 

[reeldive]

Reeldive if you're referring to mine, thank you :blinking:

Your Welcome

 

[Walter]

Maybe not until the overpressure valve pops, but I'd be one of those people with a full wing that you guys would be regarding with suspicion.

Darlin', I'm suspicious of you anyway. You're way too smart.

I'm suspicious of folks who do things without knowing why, folks who aren't thinking. You, my dear, are always thinking, always asking why. That's an excellent trait.

 

[DennisW]

If it was 20 extra pounds then you would be over-weighted. A couple of pounds negative (or whatever you needed to start with to be neutral at the end of your dive after your tank air was consumed) is proper weighting.

I am surprised there are not a few divers out there with salinity test kits. Then they can determine the salt water density value to 10 decimal places and use cheese grater type tools on the dock to shave off the three of four extra grams of unnecessary lead weight to compensate.

I've never, ever put on more than 12 lbs of lead. It would be pretty humorous if I were to actually try to enter the water with 20 lbs of extra lead.

 

[CJ-62]

I have no problem with jumping off the boat and immediately descending, if conditions require it. We did this in some of the current diving in Cozumel.

But my diving at home is almost always in flat water with very poor visibility, and making sure the team is close together and prepared to descend at the same moment is often critical. I suspect, as Soggy says, that I'd have enough air trapped in various places to be able to stay on the surface by swimming, but I'd simply rather not. Being relaxed and comfortable and not at all winded is a very good place to start a dive for me, and I can see no detriment whatsoever to having my wing inflated when I get in the water.

Maybe not until the overpressure valve pops, but I'd be one of those people with a full wing that you guys would be regarding with suspicion.

Well said.

Another 'special case' for your consideration. Some of us don't require any extra lead at all. I don't carry ditchable weight as I don't need it if I use steel tanks.

As is usually the case, making sweeping generalized statements only leads to an endless list of exceptions. So it's best to pepper your statements with some conditionals.

Best of luck.

 

[shadragon]

I've never, ever put on more than 12 lbs of lead. It would be pretty humorous if I were to actually try to enter the water with 20 lbs of extra lead.

Ran into a lady diver a few weeks ago who was diving a full body 5MM wetsuit, AL80 and had 50 pounds of lead. Five - Zero... We all had a chat with her...

 

[Sideband]

Ran into a lady diver a few weeks ago who was diving a full body 5MM wetsuit, AL80 and had 50 pounds of lead. Five - Zero... We all had a chat with her...

If she is able to move around easily with a BC, tank and 50lbs of lead, I hope you were polite. Though that is probably why you went in as a group. Safety in numbers