Just finished welding a whole new bottom on mine. Doubled up the skin to above the water line. Patching those holes is a easy job. I put big timbers ( 12x12's ) accross my trailer and set the hull back down on them. Worked quite well to allow access to the bottom. Just lay it over and work on one side and lay it over the other way for the other side. I would clean all the black crap from the inside, weld a patch over the hole (from the inside ) and have the outside all cleaned up ( stainless wire wheel on a grinder )and weld a plug in the skin on the outside. You can grind the weld smooth if you want. Then patch the bottom paint. Not a big job, but dirty hard work. You can do a lot of the work yourself, if you want to save some money. A good welding shop will have no trouble. You might find some one with a mobile rig. ( welding truck ) You need a mig gun set up for aluminum. The big job is to get it ready and probably pull the fuel tank so you don't blow up. Do any other welding while you are at it, and clean out the fuel tank too. You either have to pay or do the work yourself, but always something to fix. I can try to send some pics of my project if you want. Good luck with it, Ed

FastJeff has a solution for holes in the hull that is made from aluminum disks and a special bolt. I plan to use his method next haulout because I may want a hole again later on, and it should be a lot faster than cleaning, welding, and repainting.