I had a similar boat years ago that my son and I used for fishing strip pits in Illinois. It started leaking and I got this product at a hardware store. I can not remember the name, but it was for stopping leaks in metals and may have bore a name with 'marine' in it. I believe it was from a tube or a small can and was gray or black in color. It worked great, go to either a hardware store or similar place and they should be able to help you!