How Trim Tabs Can Improve Your Boat Performance (video)

News & Tips: How Trim Tabs Can Improve Your Boat Performance (video)...

Trim tabs can cure performance problems in many boats that are overweight or underpowered, and can also help boats that are ideally packaged to better performance and greater comfort in many conditions. 

tabs on boat 
Get the best boat ride possible. Trim Tabs improve boat performance and give you more control by helping you operate your boat over a wide range of conditions.  illustration by Bennett Marine

How Trim Tabs Improve Your Boat Control

Tabs like the Bennett Marine Bolt or the M-Series Sport Tab systems are basically moveable plates that mount on the transom of the boat to either side of the outdrive or outboard. They can be lowered at the touch of a switch to provide added lift at the transom. This makes for quicker planing, particularly in boats with a low power-to-weight ratio. It's a plus when you want to tow skiers or wakeboarders, when you have an unusually heavy load on board, or when you need to get on top fast because of shallow water close-by.

And in some boats with excess weight aft, raising the transom area a few inches can also increase top speed and/or fuel efficiency as it helps the hull get fully on plane.  Raising the transom also drops the bow, which can provide a softer ride in a chop since it forces the sharper forward entry of the keel into first contact with oncoming waves.

Tabs Can Level the Load on Your Boat

Tabs can also be used to level an uneven load: a small boat with two passengers on one side and one on the other may tend to run with the heavily weighted side down, making steering difficult as well as causing the boat to ride wet and rough. Drop the tab on the low side and it levels the boat up, restoring the normal running attitude.

Tabs can also be used to purposely raise one side of the boat, which can be an advantage when running across the wind where spray may be coming aboard heavily each time the boat hits a wave. By raising the upwind side of the hull--via lowering the tab on that side--the boat in effect gets a taller freeboard on that side, and delivers a drier ride.

Trim Tabs Are Not Difficult to Install on Your Boat

Tabs are not difficult to install--anyone with basic home tools and handyman skills can do the job by following the instructions and the on-line videos. They're not inexpensive, with the electric models starting at around $450, but considering the improvement in performance they can provide, they're a good investment for many boats. They come in 9-inch and 12-inch widths in models suitable for the typical bass or walleye boat or ski rig--in general, you'll want the largest size that will fit on your transom without getting too close to the lower unit or the outer chines.

trim tab sizing guidelines
Trim Tab Span = side to side measurement
Chord = fore to aft measurement.  illustration by Bennett Marine

Bennett Marine recommends as a rule, choose at least one inch of trim tab span (per side) for every foot of boat length. (Examples: 22-foot boat = no less than 24″ x 9″, 36-foot boat = no less than 36″ x 9″. Learn more about the trim tab sizing guidelines at Bennett Marine. Remember that the largest trim tabs that will comfortably fit on the boat transom will be the most efficient.

Another alternative, considerably less expensive but useful in some boat/motor setups, is a self-leveling system like Nauticus Smart Tabs or Bennett Marine Self-Leveling tabs. These spring-action tabs are installed in the "down" position, and as the boat speed increases and water pressure builds up on them, they're forced to a flat or horizontal position.

The concept is that you get the stern lift on takeoff, when it's needed, and then the tabs flatten out once the boat is on plane and does not need the aft boost any more. They don't give the option of adjustment once you're underway, and can't be used for side-to-side leveling. However, they work very well on some packages, and at a price under $150, they're an economical fix for stern-heavy or underpowered boats. Again, installation is fast and easy.