I have the opportunity to purchase a Quintana Roo Quick John wetsuit for a great price. It is sleeveless and has only 1/2 legs. Will this provide any buoyancy, or is that usually found in the legs of most wetsuits? I just want something to keep warm, as most triathlons around here won't be held in open water unless it is really warm anyway. Any thoughts about this type of suit? Should I save my money and just get a full? Thanks for your help.