Ok well first get up beside the steering wheel, then keep jumping up until u get ontop of the wheel. Now jump down onto the arm of the sail (this make take a couple tries because its kinda hard) Once there you jump over to the sails arm beside you and do w/e you want. Persoanally i think this would go great with the one exploit that fears you off that sail and puts you to a weird white world thing. Btw this is the only way i know how to get onto the sail of the boat.