Hey, John. The say New England divers "Dive Heavy." I'm not sure if that's fact, or fiction. I was taught to dive heavy, and always have. I would think its advantageous....What do you think?
Cheers.
I dive a few pounds heavy with recreational (single tank) dives, but not really more than that. In my earliest diving days, I tried to get as close to ideal as I could, sort of as a challenge, but I eventually got away from it. The
first reason was mentioned above--fighting to get a few burps of air out of the BCD at the end of the dive. It does not take too much, though. A pound of extra lead needs about a pint of air in the BCD to be neutral. Put a whole lot of extra lead on, and you've got a whole lot of unneeded air in that BCD.
The more air in the BCD, the harder it is to dive. You control buoyancy through that air and through your lungs. As long as the air volume in the BCD brings you within a reasonable range of neutral, you can maintain control through breathing alone. Get out of that range (by ascending or descending), and you have to adjust the BCD. The more air in the BCD, the more it controls your buoyancy rather than the lungs because it makes the range where you can control with the lungs much smaller. I do a demonstration for OW students in which I go from the bottom of a 12 foot pool to the top and then back to the bottom using only my lungs, and I can do that even 6-8 pounds overweighted. When I am practicing tech diving with my steel doubles in the same pool, my range is limited to a few feet.
There is a
second reason to be a little overweighted, which I discovered on a dive trip in Mexico more than a decade ago. I was using a ScubaPro Nighthawk with shoulder trim pockets. I had learned that with a 3mm suit in salt water, I needed 8 pounds divided among the 2 waist pockets and 2 shoulder pockets to be nicely weighted and in good trim. The boat I was on only had 4 pound weights, so I had a choice of being nicely weighted but out of trm or nicely trimmed but overweighted. I was then a fairly new tech diver, so I had been getting accustomed to being overweighted, so I decided to go that route. It worked out very nicely; I was quite comfortable in the water. So, I have decided that if I have to have a bit more weight than I like in order to be in trim, that's what I am going to do.