Make Your Bumpers

Bumpers keep your boat off the walls and over-hangs of the raingutter. When wet, the walls can adhere to your hydroplane offering strong resistance to progress. likewise, at the start of the race, flat ended boats adhere to the end of the raingutter making a clean get-away very difficult. Overhangs or lips catch your boat by the deck when the water level is just right! A boat writhing under this pinch goes nowhere.

Gutters

Raingutters either have lips (overhangs) or they don't. So two kinds of bumpers are often needed. You will need wall bumpers but not lip bumpers if your raingutters don't have lips. Building them into your boat hull is the best solution, but they can be made of thin flexible materials like transparency film, toothpicks, plastic lids, etc..

Wall Bumpers

• A good size for wall bumpers is 1/4-inch long and about as wide. At this size, they can be stiff.
• Round the corners of your bumper so sharp edges don't catch.
• Glue the bumpers in pairs along the hull. Only front and rear bumpers are needed for a rectangular hydroplane hull. Protrude the rear ones out backward to act as wall bumpers at the start of the race.
• To make rear bumpers for keeping the boat off the wall at the start, cut a long, narrow slot out of the rear of the hull, leaving two rearward protrusions. They only need to stick out 1/8-inch.

Lip Bumpers

• A good size for lip bumpers is an inch tall and half an inch wide. Bumpers should be thin and springy if possible.
• Round the corners of your bumper so sharp edges don't catch.
• Only front lip bumpers are needed for a rectangular hydroplane hull. The sail acts as a pair of rear lip bumpers, already built-in.
• The best tack is to build the front bumpers into the hull.