How well a raingutter regatta racer is constructed greatly influences its performance. Boats that move in a straight line, stay above the waterline and avoid dragging the bottom tend to be better performers. Coats of polyurethane that are sanded and then topped by coats of paint can smooth the hull of the boat and reduce friction.
Mounting the keel next to the rudder keeps the boat on a straight line and makes it harder to tip. The shape and size of the sail are important; Boys' Life, the official Boy Scout magazine, suggests clipping the corners off the sail to avoid snagging it on the edges of the raingutter.
Beyond construction of the racing boat, there are recommended tips for operating the boat during competition. The race takes place down a narrow raingutter, with a Scout blowing on the sails of his boat to propel it along. It is suggested that long, steady exhalations, from directly behind and slightly below the sail, push the boat along better than short, frantic puffs from above.
The Cub Scouts, the junior division of the Boy Scouts of America, holds annual raingutter regattas to showcase the craft talents of its members. Cub Scouts purchase boat kits that consist of a wooden boat body, a sail and mast, a keel and a rudder.