A perfect blend of a high-performance dinghy and a balanced, steady keel boat, the Viper 640 is gaining traction around the country and the globe. Its growth is no surprise: Racing a Viper 640 is close, fast, and fun. Utilizing the benefits of one-design racing in a nimble and lightweight package that is welcoming for all sailors. Quantum handles the marginal gains with the most highly tuned sails to match this exciting boat. Our tuning guide will get you started on becoming the sailor you want to be.