You're much better off trying to come up with an original idea rather than trying to compete with the many businesses that are already in place. There are so many bars that I believe there is a moratorium on licenses (in a meeting the other night it was noted that some licenses are being recalled.) Scooter rentals have been tried many times and all seem to close up shop within a year or so. You'll be competing with MANY well established shops if you go the souvenir route. As for a dive shop you'll need very deep pockets to compete in a very tough industry.