Marine Accessories

If you’re shopping for trim tabs, chances are you’re wondering about the differences between the two major types on the market – hydraulic and electric. 

Bennett Marine manufactures Bennett Trim Tabs the leading hydraulic system and Lenco Marine currently makes the most recognized electromechanical system. What most people don’t know is that electric trim tabs are not new but have been around for many years. In fact, Bennett Marine originally manufactured an electromechanical system. But in the best interest of the boater, Bennett changed to hydraulic due to its many advantages.

Separating Fact from Fiction
We encourage you to ask your fellow boaters and check out the boating forums online. (Such as some of these recommended forums to the left.) To help you get started in your research, here is a side-by-side comparison on the key differences between both systems:

Hydraulic:
The motor for the whole trim tab system, the Hydraulic Power Unit, is installed inside the boat in a dry environment.

Hydraulic actuators do not rely on a seal where the shaft enters the cylinder body. Instead the seal is made on the piston face inside the cylinder where no marine growth can occur. Even if a barnacle grows on the shaft, it will not cause a leak.

If a seal on a hydraulic actuator should break, its replacement cost is about $1.00 compared to the cost of replacing an entire electric actuator.

Electric:
By placing the electric motor underwater inside the actuators, the electromechanical system is prone to failure. Electromechanical actuators rely on shaft O-rings to maintain the watertight integrity of the system.

Sand, grit or marine growth on the actuator will cut the O-ring seal letting water into the system. When the shaft of the electromechanical actuator is extended out of the cylinder body, it creates a vacuum inside the actuator. When a vacuum is pulled underwater the result is inevitably water being sucked in to fill the void. Once water enters the actuator, the boat will need to be taken out of the water and the actuator replaced.

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