I built this catamaran for "Hack The Pullback" challenge organized by LEGO in late 2021. It demonstrates functional concept of floating boat with paddle wheels propelled by two pullback motors. It is built out of LEGO Technic set 42138, two boat hulls from set 42105 and some extra parts. It also features trigger similar to one in Mustang. So wind back paddle wheels, put the catamaran on water and release trigger! You can see it in action on this video (first part shows speed build and test sail is in the end of video). Warning: using this model in water is at your own risk because pullback motors are not water resistant!