What’s New in Superyacht Stabilization?

Louisa Beckett explores the latest trends in yacht stabilization systems, from electric actuators to combo installations.

While the yacht stabilization industry continues to roll out technological advances to help counter “the motion of the ocean” each year, the biggest trend over the past decade or so has been just how crucial the stabilization system has become to yacht owners to assure their comfort on board. Today, stabilizers rank right up there with a motor yacht’s engines when it comes to essential equipment.

“I really believe that people pay a lot more attention to the stabilizers now than they did years ago [when] they ‘ticked the box’ and said, ‘We’ve got the stabilizers going in,’” commented John Allen, Quantum Marine Stabilizers founder and president. “Nowadays, there’s not a boat under 90 meters that is not having a proper model test [for] the stabilizers in a model tank in advance of the construction of the boat, and there are discussions backward and forwards between the client and the shipyard about what the performance should be, and how comfortable the owner will be…. In fact, I was just talking to a shipyard we do business with, and they told me that the stabilizer is the most important piece of equipment on the boat right now.”

“The buying public is becoming more and more aware of what [a stabilization system] can do for them and their boating experience,” says Sean Berrie, CEO of Humphree USA. “It’s coming now that at 80 feet and above, you can’t sell a boat without it.”

With so many innovative new gyros, interceptors, and fin stabilizers available for a wider variety of yacht sizes and types than ever before, many owners also are including a stabilizer upgrade as part of their yacht’s next yard period or refit. “We get a lot of people who want to add an interceptor who have gyros on board. And then some, on the bigger scale, that want to add a full system from us,” Berrie says. “They have gyros, and they want to add fins and interceptors because they want to be covered.”

Here’s a look at what’s new in the yacht stabilization market today.

Gyros

Gyro stabilizer technology utilizes a flywheel spinning at high rpm to generate angular momentum, creating anti-rolling torque within a vessel’s hull. Gyros offer the advantage of reducing a yacht’s roll without requiring any fins or other appendages protruding from the vessel, potentially creating drag while underway. They typically are compact, operate on electric power, and don’t require hydraulic lines installed on board. The “sweet spot” for most gyro stabilization systems is when the boat is stopped, at anchor, or operating at low speeds.

A relatively new technology when compared with fin stabilizers, gyros were first popularized in the yachting marketplace about 15 years ago when the Ferretti Group began offering Mitsubishi’s Anti Rolling Gyros (ARG) in some of its yacht models. Now manufactured by Tohmei in Japan, there are four ARG models available today, ranging up to the 375T, which is suitable for installation in megayachts.

“We have them on a 180-foot Benetti – four 375Ts,” says Steve Gilchrist, president of Coastal Offshore X-cellence, an ARG dealer in Fort Lauderdale. He adds that the Roll-Reduction Simulation Program Mitsubishi developed for the ARG line helps his shop to determine the size and number of gyros needed to stabilize a particular hull. “It tells you which models and how many. You can dial in the roll-reduction you want,” Gilchrist says.

Most of the recent new-product introductions in the yacht gyro stabilizer market have been designed for the smaller-boat end of the spectrum, taking technology developed for larger yachts and making it more compact and efficient. In fact, small gyro units are proving so popular that a number of production and semi-custom boat manufacturers now are designing a dedicated space for a gyro in every new model they launch.

Supporting this trend, Seakeeper recently introduced the smallest-ever gyro stabilizer for recreational boats: the Seakeeper 1. Compact enough to fit beneath a seat on a center console, it’s designed to eliminate 95 percent of boat roll in boats from 23 to 30 feet in length — yacht tender territory. The flush-mounted stabilizer runs on 12V DC power, and because it is encapsulated by vacuum, consumes just 55 amps.

“Our focus has been on small boats, and bringing stabilization to the masses,” says Kelsey Albina, Seakeeper communications manager. However, she adds, Seakeeper’s range of gyros also includes units large enough to install in large yachts and megayachts, typically in multiple-unit combinations.

On the other end of the scale, in March, VEEM unveiled the world’s largest gyro stabilizer, the VG1000 SD. Suitable for installation in vessels ranging from 60 to 90 meters in length, this monster gyro will debut in Damen’s new 73.4-meter Fast Crew Supplier 7011, built for the offshore oil rig crew transfer industry and due to launch by the end of 2020. At the product launch, VEEM announced that the new VG1000 SD is designed to be a stabilization solution for the superyacht industry as well. “VEEM has commenced the production of a third VG1000SD,” says Matteo Pandolfi, sales engineer marine, VEEM Ltd. “All three are for vessels between 165 and 230 feet, with the latest being for a privately owned fast expedition yacht.”

Mid-spectrum, Italian manufacturer Quick S.p.A. has developed a broad range of gyros for the yachting sector called the MC2 X Quick Gyro Stabilizers. While the company’s most recent models have been designed for the smaller end of the boating market, Quick also offers both AC- and DC- powered gyro stabilizers for yachts displacing up to 250 tons. A recent example is the 31-meter CCN Vanadis, which launched last year with two Quick SpA two MC2 Quick Gyro X57 units installed on board.

In addition to new-build installations, Quick is seeing a growing trend in gyro stabilizer refits. “The ability and possibility to install more than one stabilizer is strategic for the refitting and retrofit market,” says Michele Marzucco, president & CEO of Quick S.p.A.

Interceptors

Adjustable vertical blades that extend downward from the base of a boat’s transom, interceptors interact dynamically with the flow of the water beneath the hull of planing and semi-planing vessels to create lift and adjust the vessel’s attitude for better performance and fuel efficiency. Commonly installed as a less-obtrusive alternative to trim tabs, active interceptor systems can sense and automatically control a boat’s pitch and roll while underway, offering stabilization benefits as well.

Depending on the yacht’s hull configuration, interceptors can make a significant contribution to comfort on board. For example, Volvo Penta offers its Active Ride Control (ARC) system, which uses interceptors to smooth out the ride in boats from 35 to 100 feet-plus, and claims that, “ARC effectively diminishes pitch and roll motion by up to 60 percent at cruising speeds.”

In late 2019, IMTRA expanded its Zipwake Dynamic Trim Control System automatic interceptor range, known for its rapid speed of operation, by adding the new Series E for boats from 50 to 100 feet. Series E includes three straight models, three hull tunnel models, and two chine models. Zipwake’s unique 3D control panel gives users precise control of running trim, heel, and heading. Thanks to IMTRA’s NMEA 2000-based network, Zipwake Series E interceptors also can be operated from a multi-function device at the helm.

On the larger end of the yacht scale, Naiad Dynamics offers as part of its diverse stabilization portfolio the automatic Motion Interceptor Ride Control System, designed for vessels up to 300 feet and over that operate in the 20- to 60-knot range. Naiad’s interceptor system includes both hydraulic and electric models. “A recent yacht application is the 69-meter Benetti M/Y Spectre, [which has] a specially designed hull by Mulder,” says Charley Egan, Naiad Dynamics technical documentation engineer. “Naiad Dynamics produced three custom interceptor blades to exactly match the contour of the transom.”

Humphree, another major player in the interceptor systems market, recently unveiled a new series designed for megayachts. “Most recently, we’ve introduced a larger interceptor series for larger vessels, called the HLS series,” says Berrie. “That’s for boats that are 150 to 300 feet.” Humphree HLS active interceptors are powered by a 24-VDC brushless electric motor, so no hydraulics are required. Twenty-five percent more efficient than trim tabs, HLS interceptors also work much more rapidly.

Fins

Active fin stabilizers are airfoil-like appendages that extend from a yacht’s hull beneath the waterline. Installed in pairs on opposite sides of the boat, they are operated by servo-motors in the hull; fin stabilization systems also incorporate gyroscopic sensors that measure the yacht’s motion. The fins are designed to create lift and dampen the vessel’s roll motion depending on the sea conditions. Fins have been used to stabilize ships since the 1930s, if not earlier, and serve the largest range of different types of yacht, including full-displacement vessels. Today, they have advanced technologically to the point where they come in a wide variety of shapes and sizes, with or without winglets and other modifications, and can be fixed or retractable. Some manufacturers also offer cylindrical rotor systems that utilize the Magnus Effect to generate hydrodynamic forces to stabilize the vessel.

In the past, most fin stabilizer systems were hydraulic, but today, there’s a growing trend among manufacturers to offer electric versions that run off the vessel’s house system, eliminating the need to accommodate hydraulic piping on board. Electric fin systems are particularly well suited to installation in yachts that also have other electric-powered equipment such as thrusters and windlasses. They also create less noise than some older hydraulic systems, which naturally is very desirable to boat owners.

“While hydraulic systems continue to be an excellent means of powering stabilizers and other shipboard equipment, there has been a trend toward electric power in recent years,” Egan says. “Naiad Dynamics has responded by adapting our fin stabilizers, interceptors, and other devices to operate with electric motors and actuators without the use of hydraulics.”

“Up until this point, most stabilizers had been hydraulic…. Instead of using a hydraulic piston running back and forth, we are using a transmission and an electric motor, and this is all on AC electric power,” says John Champion, sales manager, American Bow Thruster (ABT)-TRAC. “[The yacht] would normally have to have one generator running to support this. It’s right in line with the same amount of power required for hydraulic stabilizers.” He adds, “There is a trend in particular towards going to electric in Europe…. Electric versus hydraulic — it depends on the culture.”

ABT-TRAC recently introduced a new model, the eTRAC 370 Digital Electric Stabilizer, designed for use in yachts 80 to 110 feet in length. Equipped with a central power controller in place of a hydraulic system and designed to run on AC power, the eTRAC 370 is more compact and easier to fit on board a yacht.

CMC Marine already is known for its line of electric fin stabilizers for large yachts, the Stabilis Electra series. Recently, the company expanded its lineup by introducing a new series designed for installation in yachts from 40 to 130 feet: Waveless by CMC Marine. Featuring the same technology as the Stabilis Electra stabilizers, the Waveless series is designed to be ultra-compact, quieter, and highly efficient. Waveless fin stabilizers are AC-powered, but DC versions also are available.

Stabilizing a yacht while it is stopped in a seaway or at anchor requires a different type of fin motion than while the vessel is underway and water is flowing over the fins. This motion has been described as “swinging” or “paddling.” Today, most of the companies that offer at-speed stabilization also offer an at-rest solution as well, either using the same fins in a different mode or by installing a second set of fins designed to operate only when the boat is stopped.

When Quantum Marine first developed and patented its at-rest fin stabilization system in 1999, it essentially named the category; “Zero Speed” has become the “Kleenex” of the yacht stabilization industry. This fall, Quantum installed its latest innovation in the 70-meter Benetti refit project Freedom: the new Dyna-Foil stabilization system. Quantum heralds Dyna-Foil as the only fin system that not only can stabilize a vessel both in Zero Speed mode and underway, but is also fully retractable. “It’s great for Ice Class vessels or for an owner who doesn’t want big fins hanging off the side of the boat while going up the Amazon,” says Allen.

Late last fall, Humphree expanded its line of DC-powered electric stabilizers by adding a new series of larger fins designed for dual or quad installation in yachts from 80 to 165 feet. These fins are designed to stabilize the yacht at 0 to 30 knots, providing what the manufacturer terms “All Speed” stabilization. To power this new series, Humphree developed a new, low-maintenance 24V DC servo actuator. The fins can operate on battery power without a genset running, making for very quiet operation at night.

Side-Power is known for its unique convex Vector Fins — curved fins that work both at rest and while underway in yachts from 52 to 150 feet. The company reports that its hydraulic Vector Fins deliver about 30 percent more stabilizing power than flat fins, creating approximately enough lift to offset any drag they create while underway. This allows Side-Power to use smaller fins for its stabilizing systems than it would if its fins were flat.

“We only make what we call an ‘Any-Speed’ system,” says Prentice Weathers, Imtra Side-Power product manager — stabilizers, hydraulic, and AC thrusters. “If you go to the trouble of installing stabilizers, why the heck wouldn’t you want them all the time is … Side-Power’s theory.” Weathers explained that a vessel typically needs larger fins for at-rest stabilization, but some flat-fin manufacturers also offer smaller fins for operation while the vessel is at speed in order to reduce drag. “We just go for the bigger fin right away…,” he says. “We don’t worry about having a larger fin while at anchor, because there’s no penalty while underway.”

What is the next new innovation on the horizon for fin stabilization? Dynamic Marine Systems (DMS), maker of several high-tech stabilization systems including the DMS MagnusMaster, based on the Magnus Effect, and the DMS AntiRoll, which utilizes dual-axis fins to stabilize a yacht both underway and at rest, has just introduced a new system for vessels up to 25 meters in length that incorporates a stern thruster. “Our newest addition to the DMS-family is the DMS WaveMaster,” says Lonne van den Kieboom, DMS Holland brand and service engineer. “We just finished the prototype-phase of this new product and we are now moving towards the pilot series. The WaveMaster is based on a completely new perspective: Keep the bow pointed into the swell so that the yacht cannot roll!”

Combination Systems

Another current trend, particularly for refits, is to install systems that combine multiple different types of technology including gyros, interceptors, at-rest, or at-speed stabilizer fins — or all of the above.

Berrie reports, for example, that Jim Smith Tournament Boats recently installed both a Humphree interceptor system and a gyro system on a custom 100-foot sportfish. “Gyro and interceptor… they’re very complementary,” Berrie says. “Gyro works at slow speed and interceptors at speed. They do a nice hand-off there; it’s a nice solution.”

“Side-Power has always said that probably the ideal stabilization system on a boat is a combination of fins and gyros,” says Weathers. “As the boat increases speed, the gyro loses effectiveness, while fins are just hitting their stride.”

Naiad Dynamics offers Total Ride Control®, a custom stabilization package for yachts that can incorporate a wide variety of technology, depending on the vessel’s requirements. “To simultaneously address multiple motions such as roll, pitch, heave, and yaw, ND has a suite of standard products including fins, canards, T-foils, interceptors, trim tabs, spanning foils, air cushions, and Dynamic Hull Vanes, and will configure them to best suit the application into a Total Ride Control® system,” says Egan. “We are now beginning to see a trend of multiple devices controlling multiple motions in motor yachts. It’s something we have been doing for many years in the commercial and military markets and have been strongly advocating for its migration into the yacht market.”

Combination stabilizer systems can be expensive, of course. But if it prevents the boss’s wife from appearing in the wheelhouse with an angry expression on her green-tinged face, installing one might be well worth the price.

This article originally ran in the December 2020 issue of Dockwalk.