Thanks for the suggestions! I honestly have never repaired aluminum before, but I did work for a state park where they rented out aluminum canoes' and every once in a while the renters would punch a rock through the bottom and I had seen several of them which had been repaired by cutting out a damaged section, and welding in a new patch. They'd grind it flat on the exterior and leave it ridged around the patch inside. That was kind of my reference for asking around. I know that welding aluminum is very difficult to say the least.
If I was patching it myself, I would probably go with the rivet method, and may yet do that since I am an absolute complete amateur at welding and never tackled aluminum before.
But I'll check with Michael Mattessich there. If it can't be welded, or if he try's to weld it and it doens't work, I can always laminate a patch on with rivets. In the particular area where it is on the boat, there isn't really any structural implications, you could pretty much cut away the damaged section and the worst you would get would be some spray from the water.
Thanks for the words of wisdom!
John R.