The Challenger is Sea-Doo's first entry into the 21-foot arena. It's stylish, features quality construction and looks right at home alongside the Sea Rays and Chaparrals of the world. Step aboard, however, and the subtle differences appear. Sea-Doo takes full advantage of its compact Rotax engines, as well as a jet drive's ultralow, inline profile. Rather than a bulky engine box impeding space, occupants find a roomy interior, 7 feet by 6 feet 3 inches, flanked by dual captain's chairs forward and a wraparound, U-shaped bench aft. A walk-through transom splits the bench evenly down the middle. Each side incorporates a small sun pad designed to overhang the swim platform rather than using a giant base. Parents can sit here when the boat isn't under way and watch the kids in the water. It's also a convenient spot for skiers and boarders to sit while gearing up. Add a relatively standard bow cockpit and you've got room for 10, two more than on Sea Ray's 210 Select ($49,277 with a 300 hp MerCruiser 350 MAG MPi Alpha stern-drive) and one more than on Yamaha's 212SS ($38,299 with twin 1,052cc Yamaha High Output jet drives).