У вашего броузера проблема в совместимости с HTML5
Testing the boat with a 180 lb man aboard, it works ok
https://www.facebook.com/media/set/?set=a.1225517697464009.1073741869.613242395358212&type=3
US heavier people should build one of these instead http://m.instructables.com/id/Sawfish-foam-kayak-build-a-funtional-light-wieght-/