Among my most significant contributions to the art and science of our sport: 
After seen an account of a lost dinghy without any contact information on it cross my harbormaster's desk, I realized that mine should have some. I printed up a piece of paper with my boats's name, length, No., and my name and phone number and epoxied it inside the transom.
I used a fairly fast setting epoxy and put it out in the sun but, when I touched it to check that it was hard, it was still tacky and I messed up the finish. I figured, what the hell, and pressed my thumb into the spot making a nice thumb print.
Now, if I really need to prove whose boat it is......
After seen an account of a lost dinghy without any contact information on it cross my harbormaster's desk, I realized that mine should have some. I printed up a piece of paper with my boats's name, length, No., and my name and phone number and epoxied it inside the transom.
I used a fairly fast setting epoxy and put it out in the sun but, when I touched it to check that it was hard, it was still tacky and I messed up the finish. I figured, what the hell, and pressed my thumb into the spot making a nice thumb print.
Now, if I really need to prove whose boat it is......