Seakeeper Ride on a Catamaran: How it Works

Seakeeper Ride on a catamaran steadies the pitch, roll, and yaw that a twin hull can’t smooth out on its own. Catamarans are built for stability, and they deliver it, but two hulls can’t erase the water. Underway, wave action still moves the boat. Seakeeper Ride is built to solve that.

This guide covers what makes a catamaran feel the way it does and how Seakeeper Ride steadies it.

What is a catamaran, and how does it feel on the water?

A catamaran runs on two hulls, called demihulls, set wide apart and joined by a deck. That wide stance is important. Spreading the boat’s footprint across two hulls gives a catamaran strong natural roll resistance, so it sits flatter at rest and rocks far less side-to-side than a single-hull boat of the same length.

However, a catamaran’s stability has limits, especially once you leave calm waters.

Wave action still moves the boat. And the same twin-hull design that resists roll introduces trade-offs of its own: flatter, less intuitive turns, increased yaw and bow steering as the bow wanders off-line, and porpoising, the rhythmic bow bounce that can set in at higher speeds.

A catamaran’s stability is mostly angled at roll. Underway, pitch and yaw are still very much in the picture.

What is Seakeeper Ride?

Seakeeper Ride is a Vessel Attitude Control System (VACS)™, a category Seakeeper created.

“Attitude” is the boat’s orientation across its three axes of motion: pitch (the bow rising and falling), roll (the side-to-side lean), and yaw (the bow swinging off line).

Where older technology like trim tabs lets you set the boat’s running angle, Seakeeper Ride senses motion across all three axes and responds in milliseconds to counter it.

Here’s what it does underway:

• Controllers mount to the transom below the waterline, with inertial sensors tracking the boat across all three axes
• Rotary blades make up to 100 adjustments per second, countering each wave before it’s felt on board
• The system eliminates up to 70% of pitch and roll underway
• Proprietary variable gain algorithms tune performance automatically for the boat and sea conditions, with no calibration from the operator

It’s fully automatic from the helm. Turn it on, and it works—one less thing to manage while you run the boat.

Can you put a Seakeeper Ride on a catamaran?

Yes. Seakeeper Ride is sized for power catamarans up to roughly 55 feet, the same range it covers on monohulls.

Installation adapts to the hull. On symmetrical and semi-symmetrical hulls, Seakeeper Ride controllers mount on both the inboard and outboard sections of each demihull. On asymmetrical hulls, the controller mounts on the outboard section wherever space is available.

A Seakeeper dealer can confirm the right fit and Seakeeper Ride sizing for your catamaran.

How Seakeeper Ride stabilizes a catamaran

The core Seakeeper Ride hardware works the same on a catamaran as on any hull. What sets the catamaran apart is the software.

Seakeeper Ride runs proprietary variable gain algorithms that optimize performance across boat types and sea conditions with no tuning or calibration from the operator.

On top of that, custom software accounts for a catamaran’s unique performance characteristics, delivering enhanced underway stabilization and letting the boat bank into turns much more like a traditional monohull. The flatter, less intuitive cornering that comes with a twin hull gets reshaped into a natural, banked turn.

To make Seakeeper Ride work on a catamaran, you don’t need to do anything at the helm. The system reads the water and corrects on its own.

Real Seakeeper Ride on catamaran trial results

Seakeeper Ride’s catamaran performance comes from documented sea trials on real boats. Here’s what the testing showed:

• Freeman Boatworks 37VH, in 3-foot seas: 57% of roll and 51% of pitch eliminated
• SeaHunter 41CTS, in 2- to 3-foot seas: 40% of roll and 27% of pitch eliminated
• Invincible Boats 40′ Catamaran, in 4-foot seas: 24% of roll and 48% of pitch eliminated

Across the board, there was measurable, felt improvement in the motions that a catamaran hull leaves on the table.

Seakeeper Ride and the gyro, together on a catamaran

Seakeeper Ride owns the run. The Seakeeper gyro owns the rest.

Where Seakeeper Ride controls pitch, roll, and yaw underway, the gyro cancels up to 95% of roll while the boat sits still, at anchor, drifting, or holding position, using a flywheel spinning up to 9,750 RPM inside a vacuum-sealed sphere to generate the force that opposes roll.

Both are now sized for catamarans, and several catamaran builders already offer them, including SeaHunter Boats, which made Seakeeper Ride standard across its full catamaran line.

Because a catamaran’s natural roll resistance is high, it needs roughly 1.5 to 2 times the gyroscopic power of a comparable monohull, which is why Seakeeper’s sizing software was extended to these hulls.

Run both, and you’ve covered the full range of motion a catamaran sees, from the dock to open water.

Fast Facts & FAQs

Do catamarans need stabilizers?

Yes, catamarans benefit from a stabilizer. Catamarans have a wide twin-hull stance that resists roll and keeps the boat flat at rest better than a traditional monohull vessel. However, what a catamaran can’t do is escape wave action underway, or design out the yaw, bow steering, and porpoising that come with the hull shape.

Stabilizers add technology in addition to the unique design of the catamaran to address those motions.

Does Seakeeper Ride work on a catamaran?

Yes. Seakeeper Ride provides underway pitch, roll, and yaw stabilization on power catamarans up to roughly 55 feet, and runs custom software built for catamaran hull design to allow for bank into a turn.

It eliminates up to 70% of pitch and roll underway, the same headline performance it delivers on monohulls, tuned for the way a catamaran moves.

Can you put a Seakeeper gyro on a catamaran?

Yes. Seakeeper gyros are available and already offered on catamaran brands like Costa Custom Boats, Freeman Boatworks, Front Runner Boats, Invincible Boats, SeaHunter Boats, and World Cat.

Because catamarans resist roll naturally, they call for more gyroscopic power than a monohull of the same size, and Seakeeper’s sizing software accounts for that.

Does Seakeeper Ride change how a catamaran turns?

Yes, for the better. Catamarans tend to turn flat, which can feel unnatural to a driver used to a monohull. Seakeeper Ride’s catamaran software helps the boat bank into turns much more like a monohull, adding the lean that makes cornering feel controlled and predictable.

Give your catamaran the Ride it deserves

A catamaran gives you a stable, roomy platform to start from. Seakeeper Ride takes it the rest of the way, steadying the pitch, roll, and yaw that the water still throws at you underway, and smoothing the turns a twin hull tends to flatten.

Add the Seakeeper gyro, and roll disappears at rest, too.

Learn more about how Seakeeper Ride works or see all Seakeeper Ride products.