i work on a crewboat in the gulf of mexico, and would like ideas on exercises i can do on the boat. we are not allowed free weights. (safety issues) i can do weighted push ups and pull ups using paint buckets and things like that but give me some other ideas. im on the boat for 14days then home for 7 so i get real gym workouts at home but on the boat i want to maintain my size. thanx in advance. Bently