- 1). Go to the back of the boat and find the area that lies the farthest distance from the center of the vessel. This will most likely be 2 inches on each side of the outboard motor that is attached to the back of the boat. This will be the location for your trim tabs.
- 2). Hold one of the trim tabs on the outside, bottom area of the transom, 1/8 inch to 1/4 inch above the bottom of the boat. Mark the drill holes for your trim tab with a permanent marker. Hold the other trim tab the same distance from the center (at least 2 inches from center), and mark those drill holes as well.
- 3). Drill the holes you marked at least 1 inch down into the transom. The width of the drill bit needed will depend on the size of screw you plan to use for your trim tabs.
- 4). Squeeze a small amount of marine sealant or adhesive into the holes you drilled. Also apply some of the sealant or adhesive to the back of your trim tab bracket.
- 5). Place the trim tab carefully on the boat so the screw holes match up. Insert and carefully tighten the screws into place. Tighten the screws evenly by hand to avoid damaging the screws or tabs.