Former Motor Boat Monthly editor Jake Kavanagh explains the innovative gear available to help boaters cruise more comfortably and avoid the accumulative effects of shocks and impacts when using small vessels at high speed or in rough seas
The ability to soften that slamming motion of a fast boat at sea has been greatly helped with more advanced and compact designs of shock-absorbing seating, self-adjusting trim tabs and internal/external stabilisers.
Costs are tumbling as equipment is being adapted from the burgeoning robotics, aerospace, and drone sectors, allowing boat owners to leave much of the ride control to fast-acting computers.
Even when mitigated, the constant movement of a boat in a seaway still requires the crew to brace themselves as their body accelerates and decelerates with each wave.
This bracing is very tiring, which is why the offshore industry is increasingly using foiling vessels to transfer crew to rigs and windfarms. The teams arrive fresh and alert, rather than tired and maybe a little seasick.
The more the boat can be made to glide through (or above) the waves rather than bounce across them, the more enjoyable high-speed boating will be.
Here is some of the equipment to help make the ride smoother, and which is relatively easy to retro fit.
Suspension ‘shock-absorbing’ seating
Suspension seating for leisure craft falls comes in two main types; ‘pedestal only,’ or a fully-fitted seat.
Suspension seating can start with a simple shock-loaded platform, as demonstrated with this Scandinavian 4S unit. You would simply bolt your favourite helm seat on top and secure the platform firmly to the cockpit sole
At the other end of the scale is the fully assembled and ergonomic seat, complete with full adjustment. This one is from US maker Shoxs, model 5005, and is intended for high-speed RIBs. Note the handlebars for passengers
Pedestal only
The ‘pedestal only’ concept allows an owner to attach an existing seat to a new platform, one contains a spring or gas filled shock absorber. There is a wide range of types and designs, some pre-set, some adjustable, and some able to swivel and lock.
The travel is usually between 6-8 inches, the amount of range needed to soften each landing without providing excessive movement for the passenger. Footrests can be added which can be adjusted to the passenger’s height.
Prices for a basic sprung pedestal can start at around £100, with fitting relatively straight forward. Sometimes this is just a straight swap of the base unit into existing holes in the deck and seat base.
Fully fitted seats
The second category is the fully fitted seat. Ergonomically padded upholstery is set into a frame that has springs or pistons installed to offer a far greater degree of comfort.
The designs include ‘Bucket’ ‘Jockey’ – a saddle arrangement for rigid inflatable boats (RIBs) – and ‘Trooper,’ but with variations on each theme. Originally the preserve of the professionals, for whom a rough sea was part of the job, this type of seating is now more widely available.
Costs have also come down due to more efficient manufacturing methods, more compact designs of mechanism, and a growing market, especially amongst US-based sports fishermen.
Some more enterprising PBO readers may be tempted to adapt the suspension seats from the likes of tractors, bulldozers and other off-road vehicles, and whilst this can prove successful in the short term, the non-marine materials involved can corrode quickly in salty air.
Buying a proper marine version tends to give a better return on investment, whilst also greatly increasing the enjoyment of high-speed or rough water boating.
Interceptors
Interceptors stab a small blade into the water and are very effective for trim control with no real loss of performance. They are supplied as a complete bolt-on unit, and only require thru-hull holes for a data cable and a power supply. This is Zipwake’s E Series
Interceptors are guillotine-like blades that stab down into the wake at the transom and prove remarkably effective at levelling the boat by reducing pitch, roll and yaw.
They can be provided as a boat-specific kit to fit the design of most transoms, but the real advantage is that they can self-adjust incredibly quickly. This smooths out the ride with speed and precision, at a rate way beyond the abilities of a human pilot.
This responsiveness, often involving dozens of adjustments per second, is due to the latest inertial sensor technology and powerful electric actuators.
Basically, in ‘auto’ mode the ‘brain’ will analyse data from a series of real-time sensors and then work the blades in rapid sequence to keep the boat running at its optimal angle.
Several companies are offering these units, but the leaders are Zipwake, Humphree and Seakeeper, the latter with its own take on the concept.
Gyro stabilisers
Gyro stabilisers have become increasingly compact. This unit from US-based Seakeeper and is designed for a boat of between 21-25ft.
Once again, the compact nature of the modern electric motor has allowed for marine gyro stabilisers to become remarkably efficient.
A large metal flywheel is spun – sometimes in a vacuum – at up to 15,000 rpm, and then reacts to any movement with immediate effect.
The gyro wants to stay upright, so as the boat moves beneath it, the gyro applies a powerful force in the opposite direction.
The result is to virtually eliminate rolling, converting it to more comfortable bobbing motion instead.
Gyros can be mounted almost anywhere on board, preferably along the centreline, and only require a standard 12VDC supply.
Larger models are often liquid cooled, whilst smaller ones are air cooled. The bad news is the price, starting at around £20,000.
Adaptive fins
The new and highly articulated All-In-One system from DMS fulfils many functions. The fins can be deployed as trim tabs for high-speed cruising…
…or stabiliser fins for mid-speed cruising…
…or ‘flapping fins’ for roll reduction at anchor
Stabiliser fins are also now more common on smaller powerboats, with self-contained motors and carefully designed blades.
Leaders in supplying the smaller cruisers are the Italian OEM CMC Marine, and the Swedish manufacturer Sleipner.
A very exciting development, due to be launched at the METS trade show in November this year, is the All-In-One from the Dutch specialist DMS.
This allows a set of fins to act as both trim tabs, high-speed stabilisers, or ‘zero-speed’ flapping foils to reduce rolling when at anchor.
Fins are still usually only found on boats upwards of 45ft but are also very effective at anchor.
As a guide to what is available, we have alphabetically listed some of the main manufacturers and the type of product they can provide.
Some have some great videos on their websites to show exactly how the forces are mitigated, greatly improving your enjoyment, and endurance, at sea.
SUSPENSION SEATING
Shockwave’s SW-S2-1200 midback helm seat with deckslide
BENTLY’S
Based in the US, Bentley’s manufacture the Mariner range of suspension seats, with single shock absorb ers for crew of up to 250lbs, and double shocks for those above. Other products include a swivel base that locks every 90 degrees.
Bentleysmfg.com
SCANDINAVIAN SUSPENSION SEAT SYSTEMS (4S).
Manufacturer of a wide range of base units, in a choice of sizes and finishes, to which the boatowner can attach their own marine seats. This company also produces complete saddle seats for RIBs.
Seatsuspension.systems
SHOCKWAVE
Based in Canada and founded in 1965, Shockwave supplies both the commercial and recreational sectors with high performance seating, including high-back seats and swivel bases. Products such as the Accuride provides immediate confirmation that the shock absorbers are set correctly to the passenger’s body weight.
Shockwaveseats.com
SHOXS/KINETIX
US-based manufacturer of the Shoxs and Kinetic brands, and a major supplier to military, professional and recreational sectors. Products range from simple pedestals to bucket, jockey and troop suspension seating.
Shoxs.com
SMOOTH MOVE SEATS
Aimed mainly at the sports angler, this Minnesota-based manufacturer provides two different suspension kits, the air and ultra-smooth. The company says both kits are extremely simple to mount, install and adjust and carry a three-year warranty.
Smoothmoveseats.com
ULLMAN DYNAMICS
Founded in 1984 in Sweden by Johan Ullman MD after serving aboard a destroyer and noticing that 80% of the crew of torpedo boats suffered with back problems. The company now makes suspension jockey, bucket and bolster seats along with a series of cockpit accessories.
Ullmandynamics.com
INTERCEPTORS
Zipwake’s E and S series of interceptor are part of a fully integrated system which acts as a ‘trim autopilot’ to smooth out the cruise
BENNETT MARINE
Founded in the US in the 50s, Bennett Marine is named after its founder Charles Bennett and is a manufacturer of remote-controlled trim tabs.
www.bennetttrimtabs.com
HUMPHREE
A team of specialist hydrodynamic marine engineers founded Humphree in Sweden in 2002. The company produces stabilizer fins, interceptor trim blades and active stabilization electronics.
www.humphree.com
Humphree’s Lightning design features a built-in 25W underwater light and full remote monitoring via a dedicated touch screen. It can also be controlled via an HTML5 link to an Multi-Function Display (MFD)
VOLVO PENTA
Volvo Penta produces the QL interceptor-style blade system in two versions – QL300 and QL 450 for high performance boats. The systems have an automatic levelling function.
www.volvopenta.com
ZIPWAKE
Based in Sweden and established in 2011, Zipwake was developed to connect own brand interceptor blades to gyro sensors for fully automatic trim control. The product is plug and play and aimed at the new build and retrofit market.
www.zipwake.com
GYRO STABILSERS
The Italian OEM Quick has recently added to its range of compact MC2X of compact stabilisers, which now has 9 models
GYROMARINE
Based in Italy, Gyromarine is a single product company founded by a group of businessmen with experience in large engineering projects involving gyroscopes. Their advanced ‘driven’ system is aimed squarely at the superyacht market.
www.gyromarine.com
QUICK
A large marine manufacturing company, Quick S.p.A. was founded in Italy in the early 1980s, and produces a wide range of nautical hardware, with further manufacturing in the US. The MC2 X range of gyro stabilisers is available in 9 models.
www.quicknauticalequipment.com
SEA KEEPER
Based in California, USA, Sea Keeper manufactures a comprehensive range of gyro stabilisers from a 12V model for small craft (24ft) to versions for vessels of up to 85 feet/100 tons. Sea Keeper also provides models for the commercial market.
www.seakeeper.com
SMART GYRO
Founded in 2014, Smartgyro is based in La Spezia (SP), Italy. The company is designing and developing a full range of highly advanced gyro stabilizers for recreational and commercial marine applications.
www.smartgyro.com
FIN STABILSERS
CMC MARINE
Founded in Pisa, Italy in 2005, CMC manufactures a range of bow thrusters and fin stabilisers, with the Stabilis Electra system heralded as the world’s first electrically actuated fin.
www.cmcmarine.com
DMS (Dynamic Marine Systems)
Established in Holland in 2013, DMS introduced the Anti-roll retractable stabilizer for yachts above 30m. This was followed by the MagnusMaster rotary system, and later by the All-In-One foiling system.
www.dmsholland.com
SLEIPNER
Sleipner Motor AS was founded in Norway in 1908 to manufacture engines and propellers. Sleipner’s Sidepower brand now manufacturers thrusters, stabilisers and all the associated electronics in house.
www.side-power.com
The Norwegian manufacturer Sleipner has recently upgraded its popular Vectis range of electric fin stabilisers with a new blade design. This has proved more effective at anchor and prevents the boat ‘paddling’ forwards
VETUS
Vetus was established in the Netherlands in 1964 and has a wide portfolio of equipment with the aim of providing completely compatible systems. A range of stainless-steel fin stabilisers is available in 7 models.
www.vetus.com
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