Seakeeper 5 Gyro: Review

Much of what made our recent Riviera 43 Flybridge offshore review and revisit so special revolved around the Seakeeper 5 gyroscopic stabiliser in the engine room.

The new gyro for boats from 30-50 feet made its debut at last year's Gold Coast International Marine Expo in May when we ran the Seakeeper 5 news.

Seakeeper claims this remarkable piece of American-made engineering, costing mid-$65k supplied and installed on the aforesaid Riv', significantly improves your boat's ride whether it is at planing speed or at anchor.

Unlike fin-based roll stabilisation systems, whose performance decreases sharply at less than cruising speed, the Seakeeper works equally well from zero to full speed, it clams.

A truly transformative device, the Seakeeper proved eye-opening on the water. It turned an otherwise ugly situation — beam-on seas in the middle of the infamous Gold Coast Seaway — into one of those redefining boating experience.

Check out the rough-and-ready video, albeit with a focusing issue, at the bottom of this article.

Also at the foot of this test, you can read the independent thoughts of Captain Casey Dent after running a Seakeeper 5 on his Port Douglas-based Zulu charter boat, a 54-footer from revered boatbuilder Assegai, in all kinds of weather. This is quite some endorsement from an independent seasoned professional skipper.

Gyro-technology, while mind-boggling when you get in deep with it and ponder the numbers, isn’t that complex on face value. A schoolboy textbook definition goes something like this:

Bringing gyroscopic technology into the digital age, the Seakeeper uses unfathomably fast computer processing to adjust and dampen roll to a discernible and, let me tell you, addictive degree. The aim is a 70-90 per cent roll reduction and, with this installation of the Seakeeper 5 on the Riviera 43, we achieved a maximum of 80 per cent, confirmed Glenn Frettingham, MD of the Seakeeper importer Twin Disc (Pacific), who came along for the ride.

The Seakeeper 5 takes about 50 minutes to fully spool-up and 35 minutes to the point of stabilisation, so turn on the unit when you first come aboard. Operating power is 1500W-2000W maximum and it runs off the 240V power, as sourced from the boat’s generator which, on this Riviera 43 bound for Tahiti, could run the air-con concurrently.

As an aside, a new Seakeeper 3 DC-powered unit is available for boats up to 10t displacement, but the powerful Seakeeper 5 is the one for pleasure cruisers and game boats from 30-50ft in length and weighing up to 20t.

The unit doesn’t need to be installed on the centreline and can be mounted in multiple installations, anywhere from amidships to the transom. The Seakeeper 5 weighs a not inconsequential 358kg, but retrofitting still accounts for 30 per cent of Seakeeper’s installations, we’re told.

Since it first hit the market some six years ago, there are now more than 3000 Seakeepers installed on boats globally, with turnover doubling annually. There are more than 100 Seakeeper gyros installed in Australian boats, says Frettingham, and this Riviera 43 was the smallest rig we know of sporting one.

However, at the time of testing, Riviera had five boats in build with Seakeepers, which have fast become must-have items on luxury 50-60 foot pleasure boats. The Gold Coast boatbuilder says it now designs fully dedicated mounting spots for gyros on all its new luxury cruisers.

Spooled-up, the Seakeeper 5 spins its internal centrifugal core weight at 10,700rpm to produce 13,089Nm of anti-roll torque, which by my calculations is almost 1335kg of force applied against external wave forces and motion. That's like a football team packing down and pushing the other way.

When operational, the unit creates a slight humming noise listed as 70-72dB from a metre distance during operation. You can’t really hear the unit over the generator, but you might when you turn it off and the gyro takes some hours to wind down.

This is a trifling matter given the advantages and, well, I’m betting you will get so hooked on the stabilisation that you might sleep with the generator running and gyro on. The Seakeeper 5 would certainly open up some overnight options in otherwise rocky locations and make those lousy nights bearable.

Maintenance involves a 500-hour anode replacement, as the unit is seawater cooled with glycol-cooled ceramic bearings, and a 1000-hour general service for what is, essentially, a hydraulic brake system. Other than that, the fully-sealed unit operating in a vacuum doesn’t need much love at all. Bearing wear is the only thing we have heard of to date.

The effects of the Seakeeper 5 on the stabilisation of the Riviera 43 on the Gold Coast Seaway were dramatic. We hit a switch on the dash and the boat's motion firmed up as though we were on an amusement-park ride returning to the home straight and dismounting bay. The ride went from white-knuckled and screaming to hands off and just comfortable.

The benefits of the stabilisation mean less mal de mer aka seasickness, improved safety in respect of your footing and unsecured items going flying, easier operation of the helm controls and navigational equipment, optimised vision and on-deck access for crew and, of course, a nicer motion for everyone including family aboard.

Captain Casey Dent from
Zulu Game Fishing Charters said, simply, "they are the best," when we asked him to rate his Seakeeper 5 after a full season off Port Douglas driving the Assegai 54 Zulu.

"We are that happy about the performance of the Seakeeper we are putting one in the new 40 (the first Assegai Express) as well. They are so beneficial to charter work and clients' comfort, as well as crew fatigue on the long marlin season, that it was an easy sell to put one in the 40," Captain Dent said.

"They have a long list of benefits which I think justifies the cost...

"We can confidently work 25-knot-plus seas with no issues of discomfort for crew and passengers.

"Anchoring in the paddock fishing for reds is now a pleasure and has opened up a lot of opportunities for our charters, as for the safety working on deck… the boat has become a very workable and stable platform.

"Night-time anchoring has now opened up; and it is far safer to prep a top-class dinner with wine glasses staying on the table and not on the carpet, etc."

Seakeeper is a product that is certainly in vogue and du jour globally right now. But it’s more than just a passing fad. Irrespective of the tough economy for pleasure boats, this has been a real growth product.

Once you experience gyro stabilisation at this level on the right host boat, there’s no turning back. Some boats are inherently stable, but a lot of deep vees, flybridge fishers and luxury motoryachts will enjoy the benefits of gyroscopic stabilisation.

You can now have the best of seakeeping ability and Seakeeper stability.

One last thing, Captain Dent texts to my phone: "We ran the Seakeeper 98 per cent of the time last season and had no issues raising fish, if anyone is worried about acoustic issues. In fact, the bait presentation was improved by less roll."

Specifications: Seakeeper 5
Boat Installation: Riviera 43 Flybridge
Price As Tested: About $48k retail at time of writing, plus installation of about $12k-$17k
Rated Speed: 10,700rpm
Angular Momentum at Rated RPM3: 5000nms
Anti-Rolling Torque at Rated RPM: 13,089nm
Spool-up Time to Rated RPM: 50 minutes (10,700rpm)
Spool-up Time to Stabilisation: 35 minutes (9035rpm)
Spool-up Power: AC Motor 2000W max,; DC control 180W
Operating Power: AC Motor (sea state dependent) 1500-2000W; DC Control 110-230 VAC (+/- 10%),50/60 Hz, Single Phase
Sea Water Supply to Heat Exchanger: 30lpm max
Ambient Air Temperature: 0° - 60°C
Weight: 358kg bolt-in installation
Length x Width x Height: 0.765 L x 0.757 W x 0.628 H (metres)
Noise Output: At full operating RPM, steady state noise measured in the factory at a 1 meter distance measures 70-72dB.  (Sound levels may be higher during spool-up)
More from Twin Disc, the Seakeeper importers, at www.twindisc.com.au, www.seakeeper.com and
www.rivieraaustralia.com in respect of the Riviera 43 Flybridge and other installations.