I would not buy a "ski" shortie if I were buying new but if I already owned one, then I see no reaon not to give it a try. I use only a skin if the water is warm enough and then only for the sun/abrasion/jellyfish protection it provides. I would not risk a big dive trip on it, I hate to be cold, but for a single dive in warm water, what the heck, you can always rent/buy a heavier suit if it turns out you need more for the kind of diving you do. For me, in 80 deg + water it would be fine, below that, I want more. Also, the effects of heat loss add up and a wetsiut that is "just enough" on the first dive is usally not enough on subsequent dives, thats the reason I usally like to dive with a little more exposure protection that I think I will need. You can always flush a little water through the suit to cool off but not a lot can be done about being cold after you start the dive.