For a sailboat to work at all, you need a part of it that “stick” in the water. Wind-powered “planes” can't work for that reason (and no, gliders aren't powere

For a sailboat to work at all, you need a part of it that “stick” in the water. Wind-powered “planes” can't work for that reason (and no, gliders aren't powered by the wind, and you can't have a ground-effect glider either) So the best you can do is have just a foil that sticks in the water while having everything else out, which is basically what every modern race boat is doing.