Uncompromising Race Boat

The Viper 640 is a two to four person, high-performance sports boat. At 21 feet long and only 748 lbs, it combines the stiffness of a keelboat with the acceleration and planing abilities of a dinghy. 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. It 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 sail makers and strictly controlled through class rules, which encourages the development of tuning techniques with the help of the best sailors and sail makers. The national class association enforces these rules to assure owners that they will race in truly equal boats. There is also an organized Texas Fleet for the Viper.


Rave Reviews - Welcome to the snake pit!

“It handles a lot like a dinghy but it’s not a dinghy… I don't think you can call it a keelboat. It’s something in between....It’s fast, comfortable to sail and well balanced. Upwind, the boat's fine bow slices through the water. Downwind, it gets up and planes.” - Paul Bieker. " When you first take off downwind in the Viper, you realize that the boats are fast, real fast…… and then the perma-grin sets in as the funmeter get pegged." Scott Nixon.


Viper Class at HYC

Viper Class Texas Fleet

Description and Technical Specifications

LOA: 21’-1”
LWL: 19’-1”
Beam: 8’-2”
Draft: 4’-6” w/Keel Down
Weight: 749 lbs.
Ballast: Lifting Bulb Keel. 271lbs (including 220 lb bulb)
PHRF: 111
US Sailing Portsmouth Yardstick 70.4
Crew: 3 or 2. Typical competitive crew is three people and a weight of 500 to 600 lbs