Hi Don..

...

Has anyone else had their Honda gas cap fall off?<<

I've had the gas cap on my "new" (to me) Seagull fall into the drink when I first mounted it on Stargazer. I essentially did as you did and poured in a pint and covered the opening with a baggie. That pint took me out of the slip, then back in after the sail was over <GG> Harvey/ Ga M-17 Stargazer #294