Rondar Raceboats later took over construction and committed to new molds. Drawing on its experience building high-performance dinghies, the company produced a rejuvenated Viper 640 that the class authority describes as immensely strong.
Design and Construction
Bennett’s hull form is purposeful rather than decorative. The topsides flare strongly aft, while the bow is very fine. The bottom has flatfish sections with about eight degrees of deadrise throughout, and the hull rocker includes a flat section fore and aft, tight around the keel fin.
Combined with a lifting keel and lead bulb, this shape keeps the boat light while providing stability in almost all weather conditions. With the keel lowered and fully bolted for sailing, draft is 4 feet 6 inches.
The hull is solid fiberglass, with wide decks that help crew movement and righting moment. The rudder and daggerboard are carbon fiber.
Sources differ on the ballast in the lead keel bulb. Some drawings show 185 pounds, while the class specification quotes 220 pounds, so a buyer should verify which figure applies to a particular hull.
Rig and Handling
The Viper carries a fractional sloop rig on a two-piece carbon mast. The mast can be stepped with a straight lift or by securing the heel near the step and hoisting it with the spinnaker halyard. The shrouds and fore stay connect quickly once the mast is upright.
A mast ram controls bend, while a retractable carbon-fiber pole supports the 380-square-foot asymmetrical spinnaker. The combined main and jib area is 252 square feet.
The boat can carry a crew of two, three, or four, though it’s aimed primarily at three or four sailors. The builder advertises it as the ultimate tactical one-design. Its deep keel and 5-0-5-styled rolled deck edge allow the crew to hike comfortably and drive the boat hard through chop.
Cockpit and Deck Layout
There are no berths below. The Viper 640 is a large open dinghy, and its cockpit is intended for athletic crew work rather than cruising comfort. The wide decks and rolled edge support hiking and quick movement fore and aft, not lounging.
That open layout also keeps the boat simple. The keel is lowered with the supplied block and tackle, then secured for sailing with two bolts. Every Viper is pre-fitted to accept an outboard-motor bracket.
Trailering, Rigging, and Launching
At 749 pounds all up on its jockey wheel, the Viper can be towed by any medium-sized car. Its two-piece mast also makes shipping and trailering easier.
Two people can readily rig and launch the boat. It floats off its galvanized road trailer in about two feet of water, making launch and recovery a two-person job at most. It can also be launched or recovered by hoist using its fitted lifting points and a bridle.
Class and Ownership
The Viper 640 is governed by strict one-design rules. A new boat includes everything needed to go racing, and the class has fleets in North America, Australia, Europe, and southern Africa. It also has World Sailing international recognition.
The Verdict
The Viper 640 succeeds as a lightweight, immensely strong one-design that combines a dinghy’s feel with a keelboat’s security. Its two-piece carbon mast, trailerable weight, and quick rigging make it a practical racing boat, while the strict class rules help protect resale value and the integrity of the competition.
Pros
- Strict one-design class with World Sailing recognition and international fleets
- Immensely strong solid-fiberglass hull, with a carbon rudder and daggerboard
- Trailerable at 749 lb all up; can be launched by two people or with a hoist bridle
- Two-piece carbon mast makes shipping and trailering easier
Cons
- Open dinghy with no belowdecks accommodation
- Keel-bulb ballast figures vary between 185 and 220 lb across drawings
