THISTLE PROCTOR MAINSAIL KK The North Viper 640 spinnaker

The North Viper 640 spinnaker reflects the knowledge we've gained by designing winning sails for a variety of sport boats

Smooth top to bottom with a powerful head and straight leech

The asymmetric is fast and easy to trim in all wind conditions

Manufactured to a full radial construction

The RHC mainsail is our latest design and continues to win more major regattas

THISTLE PROCTOR MAINSAIL KK The North Viper 640 spinnakerThe Proctor mainsail excels in light to medium wind and is an easy sail to trim. It is relatively full up top with flatter lower sections, and the draft is slightly farther aft than the Fisher main. It is built with softer, slightly heavier fabric so it is less mainsheet sensitive but more cunningham sensitive. The traveler helps depower and balance the boat in breezier conditions.