Go cheap. You can get it caught in ropes, dropping
spinnakers etc and it can be an expensive splash. The other option is to put it in a pocket( velcro or zip up) after start. I've not lost one this way myself but people look sad and go quiet when it happens to them. You can also get a slip on cover made of wet suit material that goes over wrist to protect it. Do you have a timer somewhere in boats instruments? A newish race boat should have something in there somewhere.