Wedge-shaped riding sail prevents ‘flogging’

To the editor: I would like to add an addendum to Geoffrey Van Gorkum’s answer to Scott Rhoads’ question on riding to a sea anchor in a fin-keeled boat in your January/February 2000 issue. The concept of raising a single-surface sail, such as the mizzen of a ketch (of which I have had plenty of experience), does not work well because of the dead spot when the apparent wind angle goes to zero, thus causing the sail to tack. Flogging of the sail occurs at this point, which is hard on the nerves and even harder on the sail.A better scheme is to make a wedge-shaped sail, say of 20° to 30° (included angle), which will always have some lateral force on it when the wind tends to tack it. There is no shuddering of the sail when and if it changes tacks. This sail works equally well for both ground and sea anchoring. The principle has been well demonstrated on both the RVG and Saye’s Rig self-steering windvanes. Trawlers have a similar tacking problem at anchor, and using the roll-damping sail to hopefully reduce tacking seems not to have been successful, as few trawlers even install such a sail anymore. It didn’t work well for its initial task of roll-damping either.

By Ocean Navigator