38lbs sounds about right if you weigh about 400 and are wearing a 6.5 or more suit. The "rule of thumb" that I remember hearing one time is around 10% with a thicker suit.
But what worked for me was explained to me in a more advanced training course (I forget which one). Basically you get in the water with the kit on and empty all the air out of your BC. If you sink you're too heavy. You want to get to the point where you can rise by inhaling and sink by exhaling (while at the surface with an empty BC). Then as you go down you just give it a shot of air every so often and you're neutral again.
Oh and here are my stats:
HT: 6'4"
Wt": 180lbs
Suit: either a 1 pc 6.5 or a 7mm FJ+J
BC: middle age school rear inflate w/integrated weights.
tanks: mostly these steel 72 sized 3K psi steel tanks (not sure exactly what they are but we have 5 of them at the lab and I love them!))
Total wt: Have to go check, but It's about 18 lbs when I want to go heavy (to get some work done on the bottom in currents for example)
But what worked for me was explained to me in a more advanced training course (I forget which one). Basically you get in the water with the kit on and empty all the air out of your BC. If you sink you're too heavy. You want to get to the point where you can rise by inhaling and sink by exhaling (while at the surface with an empty BC). Then as you go down you just give it a shot of air every so often and you're neutral again.
Oh and here are my stats:
HT: 6'4"
Wt": 180lbs
Suit: either a 1 pc 6.5 or a 7mm FJ+J
BC: middle age school rear inflate w/integrated weights.
tanks: mostly these steel 72 sized 3K psi steel tanks (not sure exactly what they are but we have 5 of them at the lab and I love them!))
Total wt: Have to go check, but It's about 18 lbs when I want to go heavy (to get some work done on the bottom in currents for example)