I agree - the water shoes are great idea. When I went, I saw people with wetsuits, people with just the vests. When they weren't in them, hey had either just their swim suits . When not wearing those and walking around, a swimsuit is fine and personally, I'd wear a cover up when not swimming.
Remember, they will provide dolphin save sunscreen for you.
Wetsuits are good for the dolphin swim as it is kept at the best temperature/salinity for them to live in. Most of us are not used to that. Though it was warmer than the Maine water up here that people swim in.
Side note - it's not real coral, which is why you are allowed to stand on it. It's just cement or something, dressed up to look like coral. Just don't want to see anyone get flamed.
Cheers!