Stability 60 SWATH - the practical superyacht
February 26, 2008 Stability Yachts is building a very non-traditional catamaran-based super yacht with SWATH (Small Waterplane Area Twin Hull) technology to reduce motion at standstill and at speed. SWATH technology has been previously used by the military and for deep-sea research ships, but prior to now, has not been available in a private yacht. The hull form reduces the upward forces on the vessel as the waves pass through. The biggest advantage comes in a beam sea because the technology significantly reduces the vessel’s vertical movement and totally eliminates the quick jarring movements.
The key design issue addressed with the Stability 60 is, as the name suggests, stability. The designers set out to develop a boat that is stable in almost all conditions you are likely to encounter, and to be far more comfortable in less common, very rough conditions.
The vessel can go almost anywhere and does so at a miserly 3 mpg at 8 knots and 1.8 miles per gallon at 20 knots with top speeds approaching 30 knots.
When in quiet seas, the SWATH stability is not required, so the hulls can be raised out of the water with the push of a button, turning the boat into a power catamaran. We’ve always been big fans of adaptable vehicles, and the ability to run in 2 feet deep water as well as offshore makes this boat unique - the vessel changes its operating characteristics to accommodate your needs and the existing conditions!
The project called for a disabled person confined to a wheelchair to be able to operate the vessel and live aboard without assistance, but the resultant design achieves much more. Blessed with the massive usable floorspace of a catamaran, and the stability of a much larger boat, the entire package has a draft of just eighteen inches and will happily run up onto a beach to offer an on-water all-mod-cons beach shack with shaded sand and water beneath.
In high seas, the SWATH technology enables a 5’ wave to pass “through” the boat without causing rocking and pitching, and the built-in elevator and SWATH set-up combine to offer a purpose-built water-level swimming diving and boating platform and effortless boarding from any level. With joystick manoeuvrability, an easily reconfigurable interior, excellent ventilation for tropical climates, as close as you can get to unsinkability and advanced limp-home design no matter what, the boat is a winning design.
The most obvious advantage of the Stability Yacht is its practical nature – even the roof is reinforced so it can land a small helicopter – it’s accordingly a blank canvas of possibilities. This makes the boat a wonderful water-borne platform for diving, flying, fishing, watersports and entertaining. Indeed, there’s even a waterslide that can be hung over the front – a shiny tarpaulin on the large curved surface does the trick. With its large stable deck, it’s also a natural party boat.
The adaptability goes well beyond that too – as the boat has a lift and one large floor with 5.5 ft wide access, changing the interior is easily accomplished and the stability of the vessel allows most normal home furnishings to be secure with minor alterations, significantly opening up the potential for getting what you want. So the boat can be adapted for different needs, or set up for specific needs - party animals, families, fisherman, live-a-boards, and the disabled can be easily accommodated.
The yacht has been designed with a lot of thought and the performance of every function required at sea is simple and easy. The yacht meets all federal disability codes and at the same time, logical design features you won’t see elsewhere have been added. The entire boat is easy to clean by design, with areas that trap water and dirt eliminated. The owner of a Stability 60 recently hosted a party. Several days later, that same owner was going offshore fishing with friends. To prepare the vessel, he rolled up the carpet and replaced the furniture with his patio furniture. Upon returning from fishing, he pressure washed the entire vessel-inside and out.
To most people who own a boat, that sounds like a lot of work because of the small passageways and narrow stairs into the cabin and over the gunnel to the dock. Changing the furniture is easy because there are no inclines or stairs and the elevator delivers everything to dock level.
With the jet drives, extremely light weight, and 18 inch shallow draft, the designers have even developed a system that allows you to winch yourself afloat if you should run aground. It means the boat is at least partially amphibious, and could be used to explore islands and live with nature whilst treading lightly. Indeed, develop another winching system to enable the Stability to be moved on land, and the craft might become a new class of portable home.
As a diving platform, the elevator makes dealing with a scuba tank and weight belt easy. Instead of using your last energy to climb a ladder with your weight belt and tank making you feel how heavy you are, the elevator submerges two feet below the water so you can float on and then be lifted to deck level.
The stability 60 might look vulnerable but it has been designed to be near to unsinkable. The vessel has separate sealed compartments all equipped with pumps. Even with most of its compartments damaged, the vessel will still get you home. Even if all compartments are compromised, it will not sink.
Safety features not normally available on other vessels include system redundancy. The port and starboard engines are totally separate systems with their own fuel tanks, batteries and electrical loads. If a fault occurred that caused the port batteries to discharge, you can temporarily link the starboard to the port system and recharge the batteries. The normal diesel reliability is therefore enhanced because they are totally isolated from each other. Therefore, the chance of losing both engines is quite remote. The engines meet Tier 2 emission standards and will run even if you loose an alternator or plug your water intake. When the water intake is plugged the engine will run at slow speed with internal water-cooling.
The vessel runs level, not bow up. There are no stairs to negotiate because everything is on one level and of course the vessel is stable in the SWATH operating mode. This makes walking on the vessel relatively safe. There are no exposed propellers, so you are safe if you are in the water and someone starts the engines by mistake.
Fire is always a more frightening experience on the water, especially if you are trapped on the vessel. The structural material of the Stability 60 is non-flammable.
However, if you add burning fuel, the heat will decompose the material. An optional A fire suppression system is available for the engine compartments. This system automatically shuts off the diesel fuel and extinguishes the fire.
Docking is made simple by joystick control; with computer controlled commercial jet drives the boat moves sideways when you push the joystick in that direction. Pushing a button launches the anchor and another button is pushed to retrieve it. The anchor automatically stops when it is fully retrieved. Cleaning is simple there are no areas to trap water and dirt; even the stanchions are secured below the deck. The entire boat can be cleaned in less than 1 hour. There is standing access on all sides of the engines to simplify routine maintenance.