DBMIBS 2025: Dometic DG3 Gyroscopic Stabilizer

Dometic made quite the splash at the Discover Boating Miami International Boat Show this year. They introduced the DG3 gyroscopic stabilizer and with that introduction launched an advertising blitz. Ads for the DG3 were everywhere: on the floor of the convention center, on the walls, and seemingly everywhere you looked. Obviously, Dometic thinks the launch of a new gyro is a big deal and I agree.

For anyone who hasn’t been paying attention, Seakeeper has dominated the gyroscopic stabilizer space for more than a decade. Boats show demos on Seakeeper equipped boats sold many of their stabilizers including one to my family almost ten years ago. I believe the average reaction of a boater experiencing a gyro stabilizer for the first time is something along the lines of, “holy sh*t!”

Given the huge impact a gyro can have on a boat’s sea keeping ability, it’s no surprise there have been several competitors over the years. But, none of those competitors have really challenged Seakeeper’s leadership position. They have offered similar products with, at best, similar performance. Dometic, on the other hand, has taken a careful look at the existing gyro technology and set out to move the state of the art forward. So, to my eye, this is where things get interesting.

A new competitor

Dometic promises several major improvements and innovations compared to currently available gyros. I know that Dometic’s materials mostly refer to the leading gyro, but let’s not be coy. They are comparing the DG3 to Seakeeper and more specifically to the Seakeeper 3. Both the DG3 and the Seakeeper 3 produce 3,000 newton meters per second of angular momentum. With similar stabilization energy available, they are rated for similar sized boats: mid 30s to lower 40 foot range. Currently, Dometic only offers the DG3 while Seakeeper offers units with 1,000 to 40,000 newton meter per second ratings for boats from 23 to 110 feet.

Dometic looked at pain points existing gyro owners face and concentrated on improving them. To my eye, the two biggest improvements are in spin up time and energy efficiency. But those two changes aren’t the whole story. The DG3 design also focuses on reducing maintenance and improving performance.

Reduced power consumption

DG3s ship with a 48 volt lithium iron phosphate battery. During spin up, the gyro draws power from the 48 volt battery and not from the boat’s house system. In turn, the gyro returns the rotational energy contained in the flywheel at spin down. Dometic says roughly two thirds of the energy consumed at spin up is returned during spin down. Once spun up, a DC-to-DC converter draws power from the boat’s house system to both operate the gyro and recharge the 48-volt battery. The gyro accepts 12, 24, and 48-volt power. That power flexibility is likely to be particularly helpful as we see more and more boats with higher voltage house systems.

My 22-foot Cobia, powered by a single Yamaha 150, has a Seakeeper 1. The engine’s relatively small alternator means that spinning up the 1 leaves a dent in the battery. It find myself doing mental math to determine if it’s better to use power keeping the gyro spinning or use the power spinning it back up. If I knew I could let it spin down and collect most of the power, the answer would be obvious.

Spin up and down aren’t the only phases with improved efficiency. Dometic rates steady state operation at 260 to 750 watts for the DG3, depending on sea state. Seakeeper rates the 3 at 400 to 900 watts, again depending on sea state. It seems likely that some of that difference is attributable to the lower RPMs the DG3 spins. Additionally, the DG3 recovers energy from the precession or movement of the gyro’s sphere. I’m not clear how much energy is actually captured, but the theory is that the larger the sea state, the more energy recovered. In theory, that works well because larger sea states also require more power to spin the counterweight. But, I do wonder how much actual energy is recovered from precession.

I’m anxious to see what happens with smaller gyros from Dometic. In 35-40 foot power boats, there is typically substantial power available from the motors. But, as the boats get smaller, available power drops rapidly.

Faster spin up

The Seakeeper 3 reaches its stabilization speed of 6,337 RPMs in 29 minutes and reaches its full rated speed of 8,450 RPMs in 50 minutes. The DG3 reaches its 2,720 RPM stabilization speed in 9.5 minutes and takes 16.5 minutes to reach its full 4,700 RPM. Typically, generating the same angular momentum at a lower RPM requires a heavier flywheel. But, the DG3 is only 20 pounds heavier than the 3. Dometic says they pushed weight to the outer edge of the flywheel. Moving the weight out produces similar angular momentum at a lower RPM without increasing weight.

A three fold reduction in spin up speed is a big deal. In my ownership of gyro equipped boats, I often spun up the gyro before we left the dock. Generally, that half an hour or so of spinup time wasn’t problematic. But, plenty of times I relied upon a forecast of calm water and decided not to spin up. If conditions didn’t match the forecast, I then had a half an hour or so of potentially uncomfortable time on the water. Cutting that by more than two thirds is very attractive.

Launch materials also heralded the reduced spin down time. At first, I was fairly dismissive of this benefit. I’ve owned two different boats with Seakeepers and haven’t found the spin down time an issue. But, Dometic engineers pointed out that reduced time spinning reduces bearing wear. Plus, the reduced spin down time is a natural side effect of harvesting the flywheel’s rotational energy.

Reduced maintenance

The DG3 has no hydraulics and a titanium heat exchanger with no anodes. The two major maintenance tasks on a stabilizer are servicing the brake and replacing anodes. So, Dometic has eliminated both. Instead of a hydraulic braking system, Dometic uses an inverted rollerscrew mechanism, the same technology used in their all electric steering systems. This all electric actuator provides the braking force typically supplied by hydraulics. The titanium heat exchanger leverages Dometic’s expertise in long lived, low maintenance heat exchangers in their air conditioners. Dometic expects that neither of these systems will require routine maintenance. If the steering actuator I have on my 22-foot Cobia is any indication, that’s an accurate expectation. In almost five years of service, it’s never required any attention.

Active precession

Seakeeper, and to my knowledge every other gyro, uses a hydraulic braking circuit to limit precession. Gyros use braking force to lock the gyro before it has reached stabilizing speeds, retard movement near the precession limit, and to protect the gyro and boat in extreme conditions. As I mentioned earlier, Dometic uses their roller screw mechanism. But, that’s not the only difference. In addition to supplying braking force to limit precession, the DG3 uses the roller screw mechanism to push the sphere to induce stabilizing forces.

My understanding is active precession has the greatest impact on smaller movements of the boat. In larger movements, torque-induced precession moves the sphere and transfers stabilizing force to the hull. But, smaller forces acting on the boat may not be sufficient to move the sphere.

I was only on a DG3 equipped boat for a short time, but I definitely noticed reduced movement dockside. Additionally, watching the gyro showed lots of small movements not typical from my experience. Sadly, I was so focused on the experience I neglected to get video of the gyro in action.

Final thoughts

Dometic was very clear that the DG3 is the first model in what promises to be a complete line of gyroscopic stabilizers. I’m looking forward to seeing the line built out and to seeing what vigorous competition does for this market segment. Currently, the DG3 lists for $43,999 compared to $39,300 for the Seakeeper 3. That is roughly a ten-percent price difference with the new contender coming in higher. Part of that expense is likely due to the included battery and pump. Although it is a difficult nut to crack, I am wondering if either company will be able to improve on the expense. and complexity of installation. Especially in smaller models, installation expense is often 50 percent or more of the cost of the gyro. One thing is for sure, consumers will benefit from two companies vigorously competing to build the best gyroscopic stabilizer.