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.