The Viper 640 is a two to four person, high-performance sports boat. It is FUN, FAST, EASY and AFFORDABLE. The Viper makes high-performance sailing available to everyone. The open transom bails water instantly, even in extreme conditions. The Viper is simple, clean, and comfortable, with no protruding hardware and everything placed for efficiency. The Viper is light enough to be towed behind a compact car and simple enough to be rigged and sailed in under a half hour. The boat can be launched from a hoist or ramp. The 640 is strict one-design with no changes permitted to the boat as supplied by the class approved builder. The only option is sails, supplied by class approved sailmakers and strictly controlled through class rules, which encourages the development of tuning techniques with the help of the best sailors and sailmakers.