Voyager 900e: German solar boat provides proof of maritime self-sufficiency

When we talk about solar-powered boats, we are usually talking about electric boats that are powered by a photovoltaic system to provide an extra kilowatt or two in the batteries. However, the actual propulsion energy used usually still comes from the shore power grid and is stored in large batteries. People like to talk about sustainability in this context, but in fact this only applies to the consumer, i.e. the boat. Sustainability is anything but guaranteed when it comes to the actual generation of electricity.

The test boat

Not so with our test boat. If you believe the manufacturer Woterfitz from Rechlin, the Voyager 900e is a thoroughbred solar boat and requires neither a generator nor shore power. Provided there is sufficient sunshine, the Voyager 900e can theoretically be driven indefinitely. This test is intended to clarify whether this self-sufficiency, i.e. complete independence from fossil energy sources, is actually possible on the water and what driving performance, not to mention comfort, can be expected in practice.

First of all: unlike our normal one-day boat tests, we used the Voyager for a multi-day trip on its home waters, the Müritz. We travelled from Rechlin via Klink to Waren, into the Classee and finally into the Bolter Kanal. All in all, a distance of around 50 kilometres in three days. No expense was spared in terms of speed or the use of electric infrared heating, an electric cooker, an electric boiler or a kettle for tea, coffee and a hot water bottle for the photographer. And the most important thing: the shore power cable remained unused the entire time.

Layout on board the Voyager 900e

Before we come to the driving performance, a few words about the layout. As the suffix "900e" suggests, this is a 9-metre boat. The covered cockpit offers enough space for three to four people. However, only the driver's seat is permanently installed. The rest of the travelling party can sit on folding camping chairs and at a table.

What we would criticise in other sports boats, we agree with here. The reason: at a maximum top speed of 12 km/h, no excessive centrifugal forces are to be expected during abrupt course changes, so fixed seats are not absolutely necessary. The driving position is sparsely but functionally equipped. A multifunction display for engine data and navigation, a rudder angle indicator and the control panel for the 1.5 kW bow thruster have to suffice - and they do for the charter area. The steering and gears are well organised and easy to operate. However, taller people would like a little more legroom between the steering wheel and the driver's seat.

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From the cockpit, we comfortably descend three steps aft to the non-slip bathing platform with ladder, stern shower and lifebuoy. We reach the saloon via the companionway and are surprised. Large vertical windows on all sides make the interior of the boat spacious, bright and friendly. The layout is well thought out and demonstrates the shipyard's years of experience in building charter boats. The galley on the starboard side leaves nothing to be desired, with the exception of an oven. Induction hob, 80-litre refrigerator, stainless steel sink and sufficient storage space in various drawers are absolutely suitable for cruising. Dining is on the opposite side to port. The large table here is height-adjustable and offers space for four people.

Below deck

In the forepeak - which cannot be separated - there is a double berth with space for two people. To the left of the staircase is the wet room, which is appropriately sized for the boat. It is also functionally equipped with a pump toilet, washbasin and shelves and, like the entire saloon, offers headroom of two metres. A shower is only available as an option, which leads to deductions in the B grade. An outdoor shower at the stern, on the other hand, is standard.

The owner's cabin is located in the stern. It extends across the entire width of the boat and is ventilated and lit via bulleys. The 1.8 metre wide and 2 metre long bed is comfortable and well upholstered. Less comfortable is access to the cabin, which is only possible in a very stooped position. For elderly crew members (like the tester), one or two grab handles would be desirable. An infrared heater installed on the rear wall serves as a heat source on cold days.

The deck of the Voyager 900e is safe to walk on thanks to the continuous anti-slip structure, with handrails all round the cabin roof and the stainless steel railing on the foredeck providing support. The cabin and wheelhouse roofs are reserved for the solar panels and must not be walked on. An anchor locker, three cleats on each side, two bilge pumps (manual and electric) and a well-dimensioned rubbing strake ensure active and passive safety.

The test drive with the Voyager 900e on the Müritz

The workmanship of the entire boat, the technical installations and the interior fittings give no cause for criticism. Let's move on to the technology and driving behaviour. In the charter version we tested, the propulsion system is a licence-free 6 kW pod electric drive from E-Propulsion with a thrust of around 1,000 newtons. Alternatively, a 10 kW version from Baltico can also be ordered, which should make the boat a few kilometres per hour faster in purely mathematical terms. The theoretical hull speed is around 14 km/h. Our series of measurements with the 6 kW motor ends at just under 12 km/h top speed. The best speed was at 1,300 rpm and 10.5 km/h.

If you want to drive completely self-sufficiently, provided there is enough sunshine, you can reduce the speed to around 8 km/h. The motor then draws 1.4 kW from the 24 kWh battery, which corresponded exactly to the amount of energy generated by the solar generator during our tour. In this driving mode, the range would actually be theoretically infinite.

In terms of handling, the Voyager 900e is undoubtedly one of the best-natured representatives of its kind. The turning circles are extremely tight thanks to the pod drive and bow thruster, and weight shifts while travelling have virtually no influence on course stability. Wind, on the other hand, does. With a moderate crosswind (3 Bf), the course had to be corrected from time to time. The shallow draught of 0.6 metres and comparatively voluminous superstructure take their toll here.

Manoeuvres with the Voyager 900e

Mooring and casting off manoeuvres are easy even in the tightest of spaces. The precisely manoeuvrable pod drive also shows its advantages when reversing. The motor and on-board electrics are powered by a 24 kWh LiFePo battery with a safe 48 volt operating voltage. Without any recharging, this amount of energy would theoretically be sufficient for around 70 kilometres of cruising at 10 km/h.

During our three-day test drive, the energy reserves never dropped below 65 per cent. And this was despite the fact that we deliberately did not do without any comforts such as a fridge, evening heating or the aforementioned kettle. The 2.4 kW solar system recharges with around 1.8 to 2 kW when the sun is shining. When the sky is overcast, the value drops to 500 to 700 W, and when it rains it was only a meagre 100 W. To bring the charge level from 75 per cent (harbour night) to 100 per cent (on departure), we needed around 3 hours of sunshine.

Let's summarise: The question was whether it was possible to be completely self-sufficient on a boat. The answer: yes, in summer. With the Voyager 900e, the designers have achieved a good compromise between size, efficiency, speed and living comfort.

And at a price that is definitely competitive. Around 156,000 euros is no bargain for a 9-metre touring boat made in Germany, but if you take into account the lack of fuel bills and lower maintenance costs, frequent boaters quickly gain an advantage. In our experience, the Voyager 900e comes very close to the ideal of a sustainable touring boat for summer use on inland waterways.

Technical data

• CE category: D
• Length: 9,00 m
• Width: 3,00 m
• Depth: 0,60 m
• Weight: 2,750 kg
• Fresh water: 220 l
• Waste water: 260 l
• Engine power: 6 kW
• Battery: 24 kWh LiFePo
• Solar cells: 2.4 kW (peak) Inverter3 kW
• Price: 156.000 €
• Distribution: www.woterfitz.de

Measurement results

* without solar recharging

Conclusion

The Voyager 900e is the perfect choice for anyone who wants to travel sustainably and with low operating costs on inland waterways. It offers a good compromise between size, efficiency, living comfort and purchase price.

Advantages

Self-sufficient drive

Good-natured driving characteristics

Good living comfort

Disadvantage

Low speed