Maybe the question I SHOULD have asked is, "When are you too old to sail a catamaran?"
The day I'm thrilled to be sailing a Sunfish, is the day I KNOW I'm too old for real sailing! The greatest danger of sailing a Sunfish, -is death by embarrassment or ridicule.
Sailing a Sunfish in 20 is a blast. Try jibing one when it's blowing. Helluva lot harder than a cat. Don't be disparaging the Sunfish. It's been around 62 years.
