Dometic SeaStar XPA Steering

Electric power-assist ushers in a new era in DIY marine steering upgrades.

SeaStar Xtreme Power Assist
Dometic’s new SeaStar Xtreme Power Assist (XPA) system requires less than an hour to install on an outboard with an existing rack or rotary SeaStar cable-steering system. Courtesy Dometic

Dubbing this a new turn is not hyperbole. Dometic Marine’s SeaStar Xtreme Power Assist (XPA) steering was designed to integrate with a boat’s existing SeaStar cable-steering system, turning it into electric power steering. It is fundamentally different from electric-helm systems on the market because it doesn’t increase the load on the mechanical helm or cable. Because it mounts easily to all major outboard brands, works with existing steering cables, and requires only simple wiring, do-it-yourselfers can complete installation in about 30 minutes. It doesn’t matter if the boat has rack or rotary mechanical steering, or whether the helm is standard or tilt.

Once XPA is installed, the steering cable only turns the power-assist unit, while an electric steering actuator moves the engine load. This eliminates steering torque through the wheel and allows nearly effortless steering at any speed.

Steering improvement aside, it’s reasonable to ask why. Dometic already offers SeaStar standard and No Feedback (NFB) mechanical steering, SeaStar hydraulic steering, Optimus electrohydraulic steering and Optimus all-electric steering.


Dometic says it engineered XPA to fill a gap in the line and a specific niche in the boating market—boats with single outboard power from 90 to 200 hp that are not traditionally rigged with hydraulic steering. This means pontoon boats, aluminum fish-and-ski types, aluminum bass boats, small center-consoles and the like. Given that XPA is an easy upgrade to existing boats of all ages with old cable steering, there is tremendous aftermarket potential as well.

SeaStar XPA on an outboard
Dometic’s SeaStar Xtreme Power Assist (XPA) system results in nearly effortless steering. Ron Ballanti

My first test of XPA came on Lake Coeur d’Alene in Idaho aboard a Lund 1875 Crossover XS powered with a Mercury 150XS outboard. I did not feel the expected steering torque through the wheel, and after getting accustomed, I loosened my grip on the wheel and settled into my “two fingers draped over the wheel, cruising down the highway with the top down” groove. To test XPA’s response to quick wheel inputs, I performed a series of spins and circles, and a smooth electric roller-screw mechanism moved the motor back and forth instantly as I turned the wheel, all with nary a sound.

Pontoons can be notoriously hard to steer. Knowing this, I was also eager to feel how XPA worked on a new Bennington pontoon powered with a 200 hp Yamaha. The Dometic team converted the boat’s standard SeaStar rotary cable steering to XPA, and the open expanses of Tampa Bay in Florida provided the test track. On a comparative basis, the difference XPA makes in steering effort was even more noticeable. Pontoons are not known for nimble handling, yet XPA allowed me to track through turns of varying sharpness with ease.


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What would happen if the XPA system loses power or fails for any reason? A fail-safe system automatically reverts to standard mechanical steering. During our test, the Dometic engineer briefly disconnected the system to simulate this situation. The boat was safely steerable, albeit with a little more effort than the standard cable steering alone.

Dometic’s XPA steering is available now and retails for approximately $1,799. More information is available at dometic​.com.


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