Thanks for reply, this is also our major concern. You can see above for my reply to Angelo about how BSAC might offer an option.I was the dive club president for two years in my Alma matter WAY back. First and foremost concern is that you are covered by the university liability insurance that is used to cover other sports clubs in your uni. I wouldn't even say that I have anything to do with a dive club or talk about it or act like it if I didn't ascertain that the club is covered by such insurance (that covers the officers and all other volunteers). Make sure that you are an official club in the university covered by such insurance before you do any activities as a club.
Something I forgot to mention in that reply: none of the founding club members were BSAC; we were also curious if we could find other sources of club-level insurance for freediving people. Does anyone know if freediving communities (eg. AIDA, CMAS, Molchanov or SSI) offered any club insurance package for non-profit student clubs?