OK, you asked... :-) If you want just a sail to give the impression of a sailboat, I personally think that you need a right angle triangle, not an isosceles. If you go with the triangle shape you have, I think I would bite the bullet & remake the row using a pattern something like this;
http://www.whateverdeedeewants.com/2...dys-quilt.html
where you would applique a narrow strip for the mast & put a base for the boat. It really wouldn't be too bad. If you applique the mast, you won't need to remake the row with the sails, then just unpick the stitching for the row between the sail & the waves and put in the row of boats.The quilt looks great so far.
http://www.whateverdeedeewants.com/2...dys-quilt.html