For those seeking a luxurious, spacious, self-sufficient home with forever changing scenery and negligible operating costs, look no further than the Silent 55. Silent Yachts will debut a vastly improved version of the Silent 55, a solar-powered, 55-ft ocean-going catamaran, at the 2019 Cannes Yachting Festival in September. With double the power of last year's model, the Silent 55 will touch 20 knots (23 mph, 37 km/h), cruise all night with no emissions and commensurate running costs, and has a draft of just 3.9 ft (1.2 m), meaning it can access just about any waterway in the world.

In the normally slow moving world of yacht development, the new Silent 55 stands out as the clean marine poster child for its fast evolving capabilities. The drive-train has been completely revised, produces significantly less noise, has much larger batteries, and is now capable of permanently cruising up to 100 miles (161 km) per day on solar–power alone.

There are a number of factors which enable the Silent 55's bang-per-buck score to go off the charts, but the main variables are the ocean-going capability, the catamaran's spacious layout thanks to the 27.8-ft (8.46-m) beam, the negligible operating costs, and the draft (depth of the cat's lowest point in the water) of less than four feet. In January, 2018, a Silent 64 crossed the Atlantic in 16 days, proving you can now take luxury accommodation with you wherever you wish to go, then go inland up any waterway, and experience living there. The diesel generator's costs for getting from Europe to America ran out to around 0.12 liters of diesel per kilometer (19.6 mpg) according to Silent Yachts.

Most importantly, the Silent 55 can glide through environments that are too sensitive to allow diesel-powered craft to operate. Just as electric power is fast transforming the automotive, motorcycle and aeronautical worlds, the raft of electrical power options available on the water is likely to transform the field of naval architecture, and the capabilities of the Silent 55 bear testimony to that.

The new drivetrain combines two 250-kW (335-hp) electric motors, replacing the previous model's twin 135-kW (181-hp) motors, and a 210-kWh battery pack offers 50 percent more energy storage than the 140-kWh unit used last year.

Viewed from above, the Silent 55 looks like one large solar panel, particularly when the hard top itself is folded down flush, when it provides an unshaded solar array of 527 sq ft (49 sq m). According to Silent Yachts, the vessel's 30 panels are rated for around 10 kW-peak. The Silent 55 uses Maximum Power Point Tracking (MPPT) solar charge regulators, which, combined with the 210-kWh battery pack, provides enough capacity for all-night cruising.

The Silent 55's house load is between 5 kWh and 10 kWh per day, provided via a 15 kVA inverter. The systems require minimal maintenance and Silent Yachts cites operational costs that are substantially lower in comparison to similar sized power yachts using traditional propulsion systems.

No generator is required for the Silent 55's air conditioning and cooking at anchor, and according to Silent Yachts co-founder Michael Köhler, "the 100-kW generator is only used to recharge the batteries in the rare case when higher speed is required for longer periods of time or if the weather is bad for several days.

"What this represents to the yachtsman, among other features, is the ability to cruise for many hours at normal speed and throughout the entire day and evening at reduced speed," said Köhler, who began building solar catamarans a decade ago with his wife Heike. The couple have long been devotees of sustainable cruising and have spent 5,000 days aboard their solar catamarans, cruising more than 75,000 miles around the world in the process.

The Silent 55 to be displayed in Cannes will have the standard layout comprising a large saloon on the main deck and four cabins below decks, including a full-beam master suite in the bow area.

There are, however, five different layouts ranging from three to six staterooms with three or four heads, and a new addition to the range is a ferry version with seating for over 60 people on the main deck.

A full-width central owner's stateroom is the centerpiece in three of the layouts, with guest staterooms located in port and starboard hulls. All staterooms offer double or twin berths, and all heads include a separate shower. In addition, the flying bridge promises to allow helmsman and guests to enjoy time together underway with superior lines of sight all around the boat.

Other layouts are available on request, and the company's modular construction methodology is claimed to make designing your own layout quite affordable. The cost of the Standard three-cabin version runs to €1,394,000 (around US$1,570,000) with the four-cabin version costing just €5,000 (US$5,630) more, and other cabin options in a similar price range. There's also plenty of room to work with thanks to the 27.8-ft (8.46-m) beam of the yacht.

The Silent 55 also offers the ability to bring your own conveniences as all onboard appliances operate on the 220/110-volt system. The water-maker is powered by the solar-electric system, the galley has plenty of refrigerator and freezer space, and an efficient induction cooktop precludes the need to carry propane.

The Silent 55 is available with either a sail or kite as optional extras, though the sail option is costly, and significantly adds to the weight while cutting the yield of the solar panels in half. The 205-sq ft (19-sq m) kite option adds just €25,000(US$28,200) to the price and can offer speeds of 6 knots in light winds.

For those who aren't content with the Silent 55's cabin space, there's also a Silent 64 and a Silent 80, though the purchase price rises dramatically with the larger yachts, and the top-of-the-range Silent 80's starting price runs to €4.27 million (US$5.3 million).

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