2011 Sea-Doo 180 Challenger Low Hours, Excellent Compression. 255 HP Rotax Jet. Galvanized Trailer, Depth finder and Stereo. One of the most versatile 18-footers on the water. Gives you the space of a 20-footer with plenty of standard features, like a satellite-ready sound system with MP3 port. - 2011 Sea Doo 180 Challenger. 255 HP Rotax. LOW HOURS. Galvanized Trailer.