The Vortex Sail, Variable Geometry Proa
by Malcolm Smith
VP4 Concept Design
The sketches below show a conceptual design for a full size Vortex Proa. The sketches are not to any particular scale. The accomodation or cockpit space is provided in the nacelle mounted on the swinging cross beam. This is a rudderless design. Steering is achieved by a combination of varying the cross beam angle, and the varying the sail rake angle. Shallow draft is achieved by using a hybrid ama/vector fin (hook foil, j foil, sea hook). The sail is mounted on a leading edge wire which is tensioned between the ends of the aerofoil spars (shown in grey), and can be roller furled for reefing or stowage.
Profile
Plan
Perpective View from Forward Quarter
Perpective View from Aft Quarter
View from Forward