twin skinned mainsails with foam wing

Inspired by a mainsail made by Steve Knowland in the UK, the concept is a double mainsail with an articulated foam wing between the two layers of the sail, rotating around the mast. The aim is to a) make a more efficient mainsail and b) provide buoyancy inside the sail to stop the boat going upside down in the event of a capsize. Seems to work!

[@InYourDreams-Andia]

Cool! Seems like a stable aero foil. I'm going to build a full foam split wing *GP style* next, for my 1mtr cat. I'm also endplating the main soft sail at mo with a piece of 3mm acrylic sheet bolted to the boom, under the foot. I'll do the same with the split wing too, manual set for the twist, carbon rods inside for stiffness. Aero is basically 2 symmetrical foils, with the gap for bleed thru to keep the boundary layer intact. Also will mess with VGs (vortex gens) on the leading edge, and possibly a look at CFD for an aero keel, effective down force

[@malin5468]

Very effective buoyancy in the sail and much more aerodynamic than the globes used on most of the Mini40s. I have replayed the video a number of times. Do you think longer hulls or a wider platform would have averted the capsize? Of course neither would be legal under the Mini40 rules.

[@PerthMini40man]

Hello, the cause of the capsize was simply "driver error". If you watch you will see that when the gust arrives and the boat starts to heel, the sails are not released, and this was because I was fiddling with the camera, and did not have a thumb on the winch stick. I reach for the stick but start to ease the sails too late as the boat is already past the point of no return. I wider platform always helps but as you say, not class legal