As Dave said, keep them busy.Toys in the boat might help, cheap binoculars, towing a toy boat, fishing rods etc. Very small children must be kept inside the boat, I took out a 9month old and he and his mum sat on the floor in the aft part of the cockpit( no rear seats) and the little boy spent 20 minutes fasinated by the sail. Chasing Swans, Geese etc is fun, they all seem to know that if they paddle upwind you can’t catch them.