Early in 2024 we were approached by an experienced Australian boatman who had heard of our work with electric propulsion. He sent along a design brief that demonstrated that he knew boats and was familiar with the advantages and constraints that go with marine electric propulsion. We don’t often take design commissions for construction in other shops, but this one meshed perfectly with my interest in the possibilities for low impact, quiet cruising.
Historically, the development of power boats has always been about going faster. Cheap petroleum and advances in internal combustion fostered this trend, despite the fact that high speed boating is among our most energy intensive and polluting pursuits. Batteries still have a long way to go before they can pack the power density of a good sized fuel tank, but low speed boating can be very efficient indeed.
Solar Expedition Boat for Down Under
Hull shapes that are optimized for high speeds are inefficient at lower speeds — you have to go back almost 100 years for designs that are optimized for the upper hull speed range that is so wonderful for electric boating. Atlantic Canada’s Cape Island boats and Sam Crocker’s small fishing vessels were the mode for the hull shape for this design. A large solar canopy will allow true solar sailing on the sunny days around the summer solstice, extend battery range, and mean fewer stops for marina shore power. As batteries get lighter and cheaper, each of our new electric projects seems to include more of them.
The design brief for this boat called for a boat large enough for spartan cruising for one or two people, with a beam narrow enough to avoid extra permits on Australian roads, and light enough to be towed behind the owner’s vehicle. A large solar canopy and traditional styling were also called for. With these parameters set, the rest is just details! Construction will start in the winter of 2025, at Denman Marine in Tasmania.
Solar Expedition Boat for Down Under
At Hylan & Brown, we feel fortunate to have found a group of committed people who are interested in slowing down and enjoying the peace and quiet that comes with electric power boating. We enjoy the challenge of working with a variety of electric propulsion suppliers to figure out the best components to meet their needs and work hard to keep abreast of the best combination of new and reliable in this rapidly evolving technology.
Doug Hylan
LOA – 30’
BEAM – 8’ 2″
DRAFT – 14”
BUILDER: Denman Marine, Kettering Tasmania
MOTOR: ePropulsion Navy 6 Evo (6 kW, 48V outboard)
BATTERY BANK – 30 kWh (4x Victron 24V-300Ah LFP)
SOLAR ARRAY – 1800 W (Custom Solbian panels)
RANGE AT SPEEDS (examples)- 70 nm @ 4 kts, unlimited with solar; 30 nm @ 6 kts, 44 with solar
SOLAR RECHARGE (20% to Full) – 2 days.
AC RECHARGE – Unknown