Glen Rushworth
Guest
- Messages
- 6
- Reaction score
- 0
New to the board, trying to determine which steel tank to buy. On rental Al 80's, I'm properly weighted (after buoyancy course/51 shore dives to date) with 34 lbs. No problems carrying this set up now. Male, age 57, in a Bare Nexgen dry suit and diving cold water. I'm an air hog, so need more air. Cold water doesn't help air consumption. Last dive water temp 39 F. Air determines the length of my dives, never NDL.
This is the problem: I understand that you can remove 6.4 lbs of lead (the difference) when the buoyancy on an empty Al 80 tank is +4.4 ( positive ) and say a Worthington X 8-119 is -2 ( negative ). That I get.
What I don't understand is at the start of the dive. AL 80's are -1.4 (negative) and the Worthington is -10.9 (again negative) The difference is 9.5 lbs. How do I apply this difference compared to removing the 6.4 at the end . Do I add them together ? and then would I be underweight at the end by removing a total of 15.9. Or is 6.4 the total and I would just drop like a rock at the start. This last part doesn't make sense.
I know that I'll need to get my carried weight narrowed down again after new tanks. I'm just trying to understand the math behind it. This would help me determine which tanks to get. I appreciate any and all help. Thanks
This is the problem: I understand that you can remove 6.4 lbs of lead (the difference) when the buoyancy on an empty Al 80 tank is +4.4 ( positive ) and say a Worthington X 8-119 is -2 ( negative ). That I get.
What I don't understand is at the start of the dive. AL 80's are -1.4 (negative) and the Worthington is -10.9 (again negative) The difference is 9.5 lbs. How do I apply this difference compared to removing the 6.4 at the end . Do I add them together ? and then would I be underweight at the end by removing a total of 15.9. Or is 6.4 the total and I would just drop like a rock at the start. This last part doesn't make sense.
I know that I'll need to get my carried weight narrowed down again after new tanks. I'm just trying to understand the math behind it. This would help me determine which tanks to get. I appreciate any and all help. Thanks