This photo is of my Hobie Mirage Tandem Island. Basically an 18 foot kayak with retractable out riggers. It can be a trimaran or sometimes referred to as a 'sail-yak'.(from kayak, not from the animal). The mast is 18 foot and carries 90 square feet of sail. (roller reefing main, no jib). The 'Mirage' refers to the pedal drive system, a straight back and forward motion, that is adjustable for leg length, that drives a lateral flipper system underneath. If you have never seen one in action then you should search "YouTube" for some great videos.