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The Seakeeper Effect

Electronics Editor Ben Stein installs both a Seakeeper gyro and the new Seakeeper Ride on a 22-footer for the ultimate test.

Seakeeper made their name with their gyro’s ability to stop a boat from rolling. A short sea trial has made countless believers in their technology. For several years, Seakeeper’s name has been synonymous with gyros and only gyros. Then about two years ago they introduced Seakeeper Ride with the promise of transforming a boat’s performance at speed in the same way. My test boat, a 22-foot Cobia 220cc, is outfitted with both systems.

I first took a demo ride aboard a Seakeeper gyro-equipped center console at the 2015 Fort Lauderdale International Boat Show. My wife and I both attended and casually signed up for a demo that turned my otherwise frugal spouse into an enthusiastic Seakeeper believer. Gyroscopic stabilizers are most effective on a boat at rest. At low speeds they remain extremely effective and have less impact the faster the boat travels. That behavior makes a gyro extremely easy to demonstrate. While idling during our demoin the Port Everglades Inlet, a large sportfisherman threw a sizable wake at us, at which pointlocking and unlocking the gyro tidily demonstrated its worth. That winter, we had a Seakeeper 9 installed on our 57-foot Carver Voyager 570, Have Another Day.

Seakeeper Ride components and the tools needed to install them displayed on a table.

Seakeeper Ride components and the tools needed for the installation

I went on to cruise over 15,000 nautical miles with Have Another Day (before Hurricane Ian sank her). In that time, I found cruising at displacement speeds--an otherwise trying endeavor atop even moderate swells--a delight. Whenever we encountered significant seas or wakes before outfitting her with the Seakeeper 9, increasing speed to get the boat on plane was the only mitigation. After the installation, spinning up the Seakeeper and letting it work its magic produced a decidedly cushier ride. She gently rode up and down with nearly no side-to-side rocking.

Now, Seakeeper is onto something else. As the company’s first non-gyroscopic product, Ride is a big gamble. They’ve created a reputation with the gyro for, what Seakeeper CEO Andrew Seprevivo describes as, “hit the button, holy shit.” Ride is what they call a “vessel attitude control system” that adjusts how the boat runs through the water by generating lift at the stern to temper pitch and roll, sort of like high-tech, automated trim tabs; they say it even works on aerated stepped hulls.

To be fair, Seakeeper isn’t the first company to use a gyroscope to stabilize a boat and they’re not the first on the market to control a boat via stern mounted lift generation, either. But they have, in both cases, changed the marketplace through the marriage of physics, advanced software, and control systems.

The Seakeeper Ride installed on the stern of Stein's 22-footer.

The Seakeeper Ride installed on the stern of Stein's 22-footer.

Ride operates the boat via a pair of stern-mounted controllers, which use rotary actuators to extend bucket-shaped blades into the water to generate lift. Compared to existing vessel attitude systems, Ride is dramatically faster, making hundreds of measurements and adjustments per second. Your eyes tell you there’s an impact coming from the wave the boat is about to crash over, but instead of a bone-jarring landing, the hull seems to slide across the wave.

Ride is designed to work in concert with a gyro, and doesn’t begin to control the boat until speeds reach 9 or so knots—Seakeeper says it’s most effective at 17 to 22 knots. Ride works by deflecting water and the faster the water moves, the more control it can exert through that deflection.

Seakeeper installed Ride on my 22-foot center console as they were developing installation training materials, and more recently, Tri-Sea Stabilizers installed a Seakeeper 1 on the same boat. Thus, I have a 22-foot boat equipped with two very different but complementary stabilization systems.

Both systems are controlled via either a dedicated controller or integrations with onboard MFDs. Surprisingly, there is no communication between the two systems. But this makes sense when we consider the gyro is most effective at low speed and Ride takes over as the speeds increase. Each system does what it does best and contributes to overall comfort.

Wiring the boat for the Seakeeper installations.

I’ve spent a couple of hundred hours on the water with Ride and now a couple of dozen with both Ride and the Seakeeper 1. At rest and at low speed, the gyro effectively controls the movement of the boat and nearly eliminates roll. As speeds increase, the gyro becomes a little less effective. In my experience on this boat, the gyro remains impactful well into the teens and as the boat is fully on plane. But, at the same time that speeds are increasing and the boat is climbing on plane, Ride begins influencing the performance of the boat before nearly fully taking over above 20 knots. The result? A boat that punches way above its weight class in how it handles conditions. In fact, unless I disable both systems, I regularly find myself thinking the conditions are far better than reality has them.

The impact of the gyro is easier to demonstrate and understand. Sitting at the dock, it’s easy to get the boat rocking nearly from rub rail to rub rail with a few people’s coordinated effort. As soon as the brake on the gyro is unlocked and stabilization begins, the boat simply stops rocking.

On a smaller open boat, the gyro greatly improves the comfort. Ride does too, but perhaps more importantly, it enhances the boat’s ability to handle big water. On a rough day, I have to stop and think about what would happen if I had an issue with Ride—and I’d better. It’s been reliable, but you don’t want to get the boat out in conditions it can’t safely handle without Ride.

Seakeeper gyro waiting to be installed.

Together, these two systems make a day that might be marginal without my family comfortable even with them. This time of year, it’s awfully hot in South Florida, so a day on the water is frequently a day mostly in the water. Ride helps us arrive at an anchorage comfortably, and once there, the gyro keeps the boat flat, stable, and comfortable as we swim and cool off.

The Seakeeper 1 is designed for boats 23 to 30 feet. Part of that rating is to ensure the engines on the boat have large enough alternators to power the gyro. My 22-foot boat’s 150-horsepower engine’s alternator is a little undersized for the job, so I’ve fitted the boat with a 215-amp-hour lithium-iron-phosphate battery. As the gyro spins up it draws a peak of 40 to 50 amps for about 20 minutes before dropping to steady-state power consumption between 9 and 15 amps. The engine alternator generally keeps up with the steady-state power consumption but not the startup, and I typically put the battery on a shore-power charger about every ten trips.

Ben Stein with his family.

The author and his family on their newly stabilized boat.

Not every boat accommodates both systems. Currently, Ride is limited to boats under 35 feet and ranges from $4,500 to $10,500 for the system, plus installation. The Seakeeper Ride system sized for my boat retails for $4,500. Tri Sea Stabilizers, the company that installed my gyro, lists typical installation prices for all Seakeeper products. They say a typical Ride install for the 450, or smallest system, is $2,700 for a total cost of $7,200 for boats up to 26 feet. The Seakeeper 1 gyro lists for $16,900 and Tri Sea Stabilizers says typical installation is $13,360, or $30,260 in all. Both installation prices are for typical installs, but as with many after-market features, they can be higher if hull modification, bracing, or other work is required.

Prioritizing one system over the other probably depends on how you use your boat and the preferences of your crew. I can’t speak for yours, but I know that my crew dislikes rocking with a passion, so the Seakeeper 1 is a welcome addition to our little Cobia.

This article originally appeared in the October 2024 issue of Power & Motoryacht magazine.

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