you stay above water - maybe not 100%, but you'll definitely be more buoyant.. the thicker the neoprene, the more buoyant you'll be, as well.. I use a 3mm shorty (long arms, but legs only down to the knees) and, like I Said, that made me add two pounds of weight to get down.. The full suit I just got in - long sleeve and long legs - probably will require more weight.. Had I gone 5mm probably would have had to add another pound or two.. 7mm same thing.. if you try it, just make sure you're in shallow water or have some friends in the water with you to be safe..
They also make neoprene life vests.. I don't think they'll keep you totally above water, but from wha tI hear, they sure help you stay above water..
Friendship is like peeing your pants.. Everybody can see it, but only you can feel the warmth..