Horizontal airfoils. I like it.
In the late 60s the A-cats and C's at Cabrillo Beach YC, Long Beach, CA, used "end plate" booms. Some used a wishbone down low with Dacron filling it in. Others used a normal, for the day, boom with Ocumme ply wings. We made sure that it was very slightly HIGHER at the clew. This was not to lift the boat, but to compress the air and make the air lift. If the Park Avenue Boom thing angled down, we felt it would blanket part of the bottom of the sail.
The old Suicide class (ask Bill Roberts) was anything-goes in monohull, but with only 125 square feet of actual sail area, including mast. It became very efficient, using an A-cat style mast and wishbone main, 1950's and 60's materials, of course. Tried was an end plate on the top of the mast. Again, it was more for reducing tip vortex than lift, although it was angled up on the front for the same reason the boom was angled down on the tack. The class ruled that they had to count the tip deflector as sail area, so it was quickly abandoned.(Most booms on dinghies are faster with the boom lower at the clew, It makes for leading edge foot, instead of trailing with its tip vortex and loss of pressure under the boom.)
On the Suicide, wind resistance on the spars and hull was a major design consideration. Many of the hulls looked like missiles or long cigars to try to cut the wind. It helped.
I'm no scientist. I do teach racing for Offshore and North U so have lots of feedback from clients. I think a wing would work IF it were not counted sail area.
In windsurfing, the sailor can re-align the sail to near-horizontal and catch air to a remarkable degree. But it also slows the board so that when it floats to the water it is barely moving ahead. If he had two sails, one to go and one to lift, hmmm. Kites are the obvious answer. I'm trying to figure out how to control it alone while sailing single-handed.
Of course, a well-designed asymmetrical chute lifts our bows. Most of the time.
I have built a Formula 14 as a test-bed. I really don't care about a Portsmouth # for it. Hydrofoils will be later. I want to try it the way it is first.
But you have made me think about a wing at the top of the mast that I can also use to keep the windsurfing sail from de-powering as fast by tiny blocks and lines leading down ala C-cat wing masts to keep the fathead leach from falling off so much. The top-mast wing would help the tip vortex thing and maybe lift the boat a bit. Kites do. Or maybe the drag would negate any advantage.
We who care not about design rules get to experiment and spend our time and money!
Dave Ellis