Hey Mary,

Make him swap boats all the time. At a regatta he sails boat 1 and you sail boat 2. At the next regatta he has to sail boat 2 and you sail boat 1. Each regatta you switch. That would force him to keep both boats pretty similar and current.

Or maybe like the old cake slicing thing. With two kids the one slices the cake and the other gets to pick the slice he wants. It encourages the kid doing the slicing to make equal size slices. So if Rick is the one maintaining the boats then you are the one who gets to pick which boat you sail each time.