Old Avon Patching
The Clavey website has good set of instructions (under "resources" I think). Hopefully you can find some original Avon fabric, which is double-sided hypalon and was the best in the business for years. Clavey no longer has it, but I'm working on some sources in the UK. Key to good patching is taking your time, prepping it correctly and not using too much glue. First coat of glue should just be a "sheen" that you can see through and it gets tacky. Second coat will have a little more glue color, but no globs or streaks of glue, i.e., no glue build-up - - the adhesion is both mechanical and chemical so the fabrics need to come close together for good adhesion. use Bostik 2-part glue and follow the instructions. For on-river repairs use Tear Aid Type A or lesser quality glue that you can peel off when you get home. Tear Aid works great.