The boat looks generally battered and unpainted. A captain might be careless about the cosmetic appearance of his boat, but fastidious about maintaining his pumps and filters. More likely, if he neglects what the customers can see, he neglects what they can't see, also.

Can you judge a book by its cover? Sometimes. Learn 23 things to look for before you step aboard another dive boat in How to Spot an Unsafe Dive Boat.