Viper 640


The Viper 640 is an American trailerable sailboat, that was designed by Brian Bennett for racing and first built in 1996.[1][2][3]

Viper 640
Viper 640 sailboat 3008.jpg
DesignerBrian Bennett
LocationUnited States
No. built400
Builder(s)Viper Boats
Rondar Raceboats
NameViper 640
Boat weight750 lb (340 kg)
Draft4.49 ft (1.37 m) daggerboard down
LOA21.08 ft (6.43 m)
LWL19.08 ft (5.82 m)
Beam8.17 ft (2.49 m)
Engine typeOutboard motor
Hull appendages
Keel/board typebulb daggerboard keel
Ballast262 lb (119 kg)
Rudder(s)transom-mounted rudder
Rig typeBermuda rig
I foretriangle height21.98 ft (6.70 m)
J foretriangle base7.48 ft (2.28 m)
P mainsail luff25.62 ft (7.81 m)
E mainsail foot10.07 ft (3.07 m)
SailplanFractional rigged sloop
Mainsail area129.00 sq ft (11.984 m2)
Jib/genoa area82.21 sq ft (7.638 m2)
Spinnaker area425 sq ft (39.5 m2)
Total sail area211.20 sq ft (19.621 m2)
PHRF99 (average)

The Viper 640 is an accepted World Sailing class boat[4] and the official one-design boat of the Gulf Yachting Association for its Capdevielle Series.[5]


The boat was originally built by Viper Boats in the United States and then in 2005 Rondar Raceboats of the United Kingdom was named the official class manufacturer. 400 examples had been completed by 2018.[1][3][6]


Viper 640 flying its spinnaker
Viper 640, showing the open transom

The Viper 640 was designed to combine the planing performance of a dinghy with the stability of a keelboat. The result is a small recreational planing keelboat, built predominantly of fiberglass, with carbon fiber spars. It has a fractional sloop rig, a plumb stem, an open transom, a transom-hung rudder and a lifting fin daggerboard-style keel, with a weighted bulb, with 220 lb (100 kg) of lead ballast. The keel is retained in the down position with two bolts while sailing. The design displaces 750 lb (340 kg) and is equipped with an asymmetrical spinnaker of 425 sq ft (39.5 m2) for downwind sailing.[1][3][4]

The boat has a draft of 4.49 ft (1.37 m) with the daggerboard extended and 1.83 ft (0.56 m) with it retracted, allowing ground transportation on a trailer.[1][3]

The boat may be optionally fitted with a small outboard motor for docking and maneuvering.[1][3]

The design has a PHRF racing average handicap of 99 with a high of 111 and low of 96. It has a hull speed of 5.85 kn (10.83 km/h).[3][7]

Operational historyEdit

Cruising World magazine named the design Overall Boat of the Year and top Performance One-Design of 2002, stating "the panelists agreed that the Viper is inherently simple, offers quality construction at a great price, and is extremely fun to sail. An attractive looking boat, the Viper invites a wide range of sailors to an equally wide range of sailing."[8]

See alsoEdit


  1. ^ a b c d e Browning, Randy (2018). "Viper 640 sailboat specifications and details". Archived from the original on 15 April 2021. Retrieved 30 May 2018.
  2. ^ Browning, Randy (2018). "Brian Bennett". Archived from the original on 15 April 2021. Retrieved 30 May 2018.
  3. ^ a b c d e f Sea Time Tech, LLC (2022). "Viper 640". Archived from the original on 25 March 2022. Retrieved 25 March 2022.
  4. ^ a b Rondar Raceboats (2018). "Rondar Viper 640 - Specification - Now a World Sailing Class!". Archived from the original on 4 December 2020. Retrieved 30 May 2018.
  5. ^ "GYA Selects Viper 640 As New Capdevielle Boat!!". 2015. Archived from the original on 6 February 2020. Retrieved 9 September 2015.
  6. ^ Browning, Randy (2018). "Rondar Raceboats". Archived from the original on 10 September 2020. Retrieved 30 May 2018.
  7. ^ InterVisionSoft LLC (2018). "Sailboat Specifications for Viper 640". Sailing Joy. Retrieved 30 May 2018.[permanent dead link]
  8. ^ Alison, Betsy (5 August 2002). "Viper 640 - This fun boat is responsive and quick". Cruising World. Archived from the original on 25 March 2022. Retrieved 15 March 2022.

External linksEdit

  • Official website