I was there January 08. I wore a 3mil suit all week and was fine, never cold. I would have been ok with my 3 mil shorty, but didn’t take it. Some of the entries are rocky and a full suit may help you keep from getting scratched up if you lose your balance and fall. You will love Bonaire if you’ve never been. The reefs were fantastic and lots and lots of critters. The reef in front of Buddy’s is easy to night dive and very fun. The drive through tank station is great... One of my favorite sites was Oil Slick Leap. If you haven’t gotten the guide for the sites it is a great investment...Tells about best entries ...exits and tips for diving each site...I’m at the beach house for the weekend and am drawing a blank on the authors name but if you want it just let me know and I’ll shoot it to you when I get back Monday.