Re: Fuel Tank
looks like you removed your deck plate after all. There are lots of quality or well-made boats that do not have a solid floor like Chaparal described (let me guess--i/o bowrider with carpet and lots of padded seats?).
But even with the floor deck up it's not always easy to remove the tank. the foam blown in is a big problem. My key west was the first model year and they miscalculated and you couldn't take the tank out--had to chop it up, which is the solution for a shot tank anyway.
Per Bond-o's comment, work on that surface and if there are no holes, prime and paint with the correct paint for aluminum. Mine leaked at the bottom; some from the top corners and edges, so inspect those areas especially where the tank might be rubbing against a frame member.
hopefully all you have to do is drain and clean. replace the anti-syphon valve with a straight-through fitting and run the hose out the bilge drain hole, then use the bulb to get a syphon going. Then there are lots of posts around here for cleaning the tank.
