Trim Tabs

Adjustable surfaces at a powerboat’s stern used to alter its running trim and side-to-side attitude.

Conventional trim tabs are hinged plates on the transom. Lowering a tab creates lift at that part of the stern, which can lower the bow, help the vessel reach or maintain planing attitude and correct an uneven running angle caused by load, wind or sea conditions.

Port and starboard tabs can be adjusted together or independently, but control response may seem counter-intuitive and excessive movement adds drag or produces an unsafe attitude. Settings should be changed progressively and reduced when slowing, turning sharply or operating in conditions where the manufacturer advises it.