Originally Posted by
SUB ZERO
Thanks everyone for your responses. I should have mentioned that I would be purchasing these tanks, not for cave but for open water diving in salt. Since I am not enrolled in a cave course (yet) I do not have an instructor. My recreational instructors all dive vertically upright like sea horses so they do not know anything about trim. My tech instructor was a small woman, whose gas consumption was super low. She would dive on tanks that were very small and never needed anything above those 80s! How can she tell me which tank to use when she has not used either. Her advice was to select a tank based on your SAC rates and your physical dimensions. Best she would do is direct me to her students who are of similar height as me OR I could reach a wider demographic on this forum.
Anyway ... I thank everyone for your useful inputs. Based on Tbone's response, I think I will go with an HP 117. I have dived those in doubles and they work well.