Solar Electric Dayboat: A New Era in Boating

DB1 Featured on Cruising The Cut

Proving Pure Solar Self-Sufficiency

David Johns from the popular YouTube channel Cruising The Cut joined us aboard the T0rkmar DB1 prototype. We put pure solar-electric dayboating to the ultimate real-world test along the River Thames. The trip demonstrated that zero-emission inland cruising is entirely practical without ever plugging into shoreline mains or relying on an onboard diesel generator. Engineered for complete energy independence, DB1 continuously tops up its battery bank from its rooftop solar array—even when left on a swinging river mooring.

Designed for Effortless Boating

We built DB1 specifically to eliminate the traditional hassles of boat ownership. A motorised hardtop canopy raises and lowers at the touch of a button. Replacing fiddly canvas press-studs and zippers with an instant, fully secure enclosure.

Cruising inland waterways also means facing thick river weed, so we integrated a dedicated deck-accessible weed hatch. It lets you clear the propeller shaft cleanly in seconds without leaning over the stern or entering the water. Furthermore, the boat’s dimensions were carefully chosen so that two complete units fit neatly inside a standard ISO shipping container for worldwide export.

Technical Specifications and Setup of the Törkmar DB1

Hull and Physical Dimensions

The DB1 prototype measures 19 ft in length with a beam of just over 2 m (6 ft 7 in). Constructed with a lightweight plywood core sheathed in glass-reinforced epoxy, the hull is finished with high-build epoxy filler and spray paint for a smooth, high-grade finish. The custom vinyl-composite motorised roof weighs approximately 50 kg (excluding the solar panels), keeping the center of gravity low while providing a robust structural shelter.

Electric Motor and Drive Setup

At the heart of DB1 is a Törkmar direct-drive Permanent Magnet AC (PMAC) electric motor. Operating without a reduction gearbox, the drive delivers silent, high-torque propulsion with zero diesel fumes or engine vibration. All central controls—including solar charge management, Victron energy instrumentation, and the motor drive unit—are compactly integrated within the steering pedestal.

Solar Array and Battery Storage

Solar Panel Array: Four flat, rigid solar panels integrated directly into the roof canopy, providing a combined peak output of 750 W.
Battery Bank: A 5 kWh lithium-ion battery housed securely beneath the forward seating area.
Off-Grid Self-Sufficiency: The roof array continuously charges the battery whenever exposed to daylight, allowing the boat to achieve full energy self-sufficiency on swinging moorings.

Real-World Performance Metrics

Cruising performance logged during the Thames journey illustrates the critical relationship between speed and energy consumption:

Cruising at 3.4 mph (380 RPM): Power draw is so low that on a sunny day, the 750 W solar array produces more energy than the motor consumes, resulting in a net-positive battery charge and virtually infinite range.
Cruising at 4.4 mph (500 RPM): Power demand doubles to overcome displacement resistance, reducing the calculated range to approximately 39 miles on battery power alone.
Cruising at 4.8 mph (Full Power): Pushing toward maximum speed requires nearly 1 kW of additional power for a negligible gain in speed, bringing the estimated range down to 22 miles