I've seen some pretty big guys out there. First they have to be able to get in a boat. Second a big belly can make it more difficult to learn to roll. One guy I was teaching recently described it as "I keep getting gut hooked on the side" He meant the coaming of the cockpit. Bigger people may not have the flexibilty that may be needed. That said the super ez has a large cockpit that most can fit into. Inflatables are another vialble option that has been mentioned.