This 5 meter spritsail rig makes a canoe go really fast. It's easy to build, easy to control, easy to put up and take down. It tolerated gusts well and can be tuned for really light winds also. I use an aluminum sign as a leeboard and steer with a paddle.
Is made from a brown polytarp. It's heavier material than such tarps are usually made these days. Polytarp is a fabric woven from strips of polypropylene that's then heat-laminated to a sheet of polyethylene.
Each side and corner of the sail has a traditional name. The sides are called Foot = bottom, Head = top, Luff = front, Leech= trailing edge. The corners are called. Peak , Throat , Clew, and Tack.
The Leech and Foot are the original edges of the tarp. That saves some sewing. The other edges are cut, folded over and sewed. Sometimes I'll put a "bolt rope" cord inside for extra strength. I used a regular home sewing machine with the thickest needles I could find for it.
Here are the dimensions of the sail: foot: 101" leech: 134" head: 71" throat to leech distance: 55"
This sail is made for a mast that rakes backward at a 15 degree angle.
If your mast is vertical you you should use the other sail drawing, or your clew will be too high. The leeboard stays in the same place but the mast partner is moved a few inches back. I reduced that version of the sail to 5 sq. meters, which wise Canadians have decreed is the perfect size for a canoe sail.