Thanks Darin…the switch is easy as you can switch power on/ off without opening the pot lid to, so between races or during breaks , just switch off. However, it does mean another hole in the hull.! I think for the meantime I will carry on just opening the pot and disconnecting the battery.. I may later, if I think it is necessary , fit a switch. Incidentally, before I put the yacht in the water, I always do a couple of checks, twitch the rudder, as you say, and check the bung is in.! Thanks for your reply..