In Feb, you're probably going to want full suits. By March/April, I found a 2mm shortie was OK for me, up to about an hour. The admiral, though, was very happy to have her full suit. This was for snorkeling and shallow
scuba. If you're thinking you'll be on the outer
reefs and 30+ feet, then just go ahead and do full suits for everybody. You can always cool off, but you can't get warmer.
ID