The Viper 640 is a 2 to 4 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 effective, 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
- Fine entry, long narrow bow and pronounced cross sectional flare in
the midsection results in low drag.
- Bulb keel and wide flared beam at the cockpit provides superior stability
and enables a powerful sail plan.
- The combination of fine entry, low drag, and powerful sail plan make
the Viper superior in light air or chop.
The Viper will start planing
any similar class (SB3, Open 5.70, K6, U20, Melges 20 & 24 etc).
- The wide cockpit, superior stability and a sturdy carbon
mast make it fast and secure in big breeze.
- The hull shape means that the Viper does not go 'bow down' planing
downwind at high speeds.