Welcome aboard,
Given the situation described I doubt this could be the cause, saving the game in any situation where there is combat or you're underwater can CTD almost like clockwork.
As frustration as the experience was, don't let that taint you; this is the best subsim out there; and with what's come out since it may well be the best one ever (imo). The mods are top notch, the
only community that I know that is as dedicated to a game is Co8 for ToEE (Temple of Elemental Evil).
People here care and I've gotten a lot of help over the years from this group. Once you get the game up and running I've no doubt you'll love it, especially with GWX (in case you haven't installed it already). Once I installed that the game went from good to spectacular, it's more addicting than crack - there should be a warning label on it