given that you willnot use all the air say the last 15 cubes tehn you have 77-15 =62 cubes and the 120 gives you 120-15 or 105. almost tqice the time 105/62...
LDS right now is being cool about it - it seems as if down here, warm water and all, AL80's are the norm. I am picking up 9 tanks Thursday afternoon, returnign on Monday after work and they are only charging me for 1 day. Hope that kind of deal lasts!
I think I have heard this but can't remember. If I can do 60 minutes off of an AL80 at an average depth of 35', what kind of time am I looking at with a HP120?