Do I need trim tabs for my boat?

That means the boat is at the mercy of the sea state, but sometimes even a total glass-out can show a boat’s flaws up for the world to see – bows running high or pushing into the water, or even just out of balance because the weight isn’t evenly distributed onboard.

One of the quickest and easiest methods, aside from trimming the motor, is to use trim tabs to correct the angle of the boat relative to the water.

Trim tabs work by lowering into the water to create lift, bringing the stern up out of the water and the bow down. They can also help to provide comfort in certain sea states where softening the ride or punching through swell become important. 

They also have a safety element, according to Shane DeWitt, the product manager for Dometic, maker of the SeaStar range of boating products including trim tabs.

“The main purpose of trim tabs is to quickly bring your bow down so you can see the horizon and what is in front of you,” DeWitt said.

“A trim tab system will help to level the boat in any situation, which will give you a more comfortable ride.”

As well as helping the engine and hull to meet the water at optimal running angles can also help to get maximum performance for minimal effort, saving owners’ fuel bills.

If you’ve never experienced trim tabs before, they can be something of a revelation in terms of the difference they can make.

Trim tabs can come in two different forms; either as flat plates that hinge off the transom and alter the flow of water behind the boat, or interceptor-style blades that drop into the water to create lift.

Boats normally have a pair of trim tabs mounted on either side of the hull. They work independently of each other to get the boat level, either manually via the skipper or automatically based on the electronic smarts controlling them.

A kit usually comprises the trim tabs, the electric rams used to push them down or pull them up, and a controller and its electric harness.

Even the controllers vary widely depending on how advanced the trim tab system is; it may just be a pair of two-way rocker switches in its most simple manual application, or as easy as dials, push buttons and LED indicators for fully automated ones.

They can also vary from standalone trim tabs to ones that are integrated with joysticks and NMEA2000 systems that allow them to talk with other electronics on the boat, including the chartplotter.

Manual trim tab systems rely on the skipper knowing what they’re doing. With sea stares differing so much from day to day, sometimes working out what is the best trim can be difficult.

Remember how we said earlier that smarter trim tabs can talk to other electronics on the boat? A good example of this is trim tabs that will automatically retract once the boat is put into reverse, or even when the key is switched off as the boat is loaded up on the trailer or the joystick for low-speed maneuvering is used. 

Smart trim tabs can also monitor real-time speed and engine revs to work out when the boat is accelerating and react accordingly to keep the bow from rearing skyward.

Yes, it’s entirely possible to replace an older trim tab system with a new one, even if you’re happy to stick with the manual-adjust system.

The big benefit of this is that the interface between the skipper and the trim tabs has evolved to make them even simpler to set and adjust on the fly than before.

The latest systems feature a dial that adjusts trim from side to side – good if you have an uneven distribution of weight in the boat or windage – as well as a simple “bow up” and “bow down” function.

The more sophisticated automatic systems are also adding “favourite” buttons that can remember settings for the most used trim tab settings and a “home” button for making the trim tabs ready to pull out of the water.

The most important consideration is functionality. Do you want automated trim tabs that take care of most things themselves, or is manual adjustment all you need?

It’s also important to ensure the trim tab controllers offer enough information so that you can instantly see the port and starboard tabs’ individual status, and allow you to easily adjust them on the fly.

The quality of the trim tabs is also important. Look at the size of the hinge where the trim tabs are fixed to the hull and ensure they’re solid enough to take the punishment of trimming up your boat.

Other important factors to consider are how well the actuators are sealed against water, grit and sand, and how well the ram used to move the trim tabs up and down is protected in its housing.

Marine chandleries such as BLA and Whitworths stock multiple brands of trim tabs ranging from manual systems right up to fully automatic.

The price for a simple passive trim tab system that uses springs to create resistance can be less than $300, but those who want more control will need to dig a little deeper into their pockets, with complete packages costing from around $1100 depending on the brand. 
Going for a high-end automatic system that is fully integrated with the boat’s NMEA 2000 network will likely cost more than $3000, but the set-and-forget nature of the system will likely justify their cost, particularly if you’re regularly relying on the benefits that the trim tabs bring.

The short answer is yes. However, before you do you will need to be confident that you can drill holes in your boat to mount the tabs, and then properly seal them against water ingress and corrosion once the screws go in.

This is especially important if you have an older boat with a wood-cored transom, or are using stainless steel bolts to fix the trim tabs to an aluminium boat.

If you've ever wired up a new chartplotter or fishfinder before, you'll find adding trim tabs quite easy.

The only difficult bit could be for owners who are plugging the trim tabs into a NMEA 2000 network. You may need a special adapter to convert the trim tab's networking plug to suit the brand of network you're connecting it with.