Power Trip

Could electric boat power be in your future?


Gazing out onto Lake Starnberg, on the outskirts of Munich, I watch a fleet of boats line up side by side. They range from 14 to 37 feet long. It looks like the start of a race, but when they leave the starting line, instead of the furious sound of combustion engines roaring into action, the only sounds are seagulls protesting and water slapping against hulls. The scene is so eerily quiet because all the boats are powered by Torqeedo electric motors (torqeedo.com), built not far from here.

An electric motor for a boat is not a new notion. Moritz von Jacobi built one of the first DC electric motors that could be used to power things. Within four years, Jacobi had improved it enough that it propelled a boat with 14 passengers across a wide lake … 178 years ago!

German boating is a bit strange due to the Draconian restrictions on combustion engines on its lakes and nearly all its rivers. It was that prohibition on this very lake that provided the catalyst for the founding of Torqeedo, in 2004. Since then, Torqeedo has experienced phenomenal growth, going from being a garage-based startup to the industry leader in electric propulsion, with motors ranging from 1 to 80 hp.

In the U.S., a number of smaller lakes prohibit combustion engines or restrict horsepower, and Torqeedo is helping to fulfill the demand for alternative power. Boat builder Qwest, in particular, has embraced Torqeedo power for its line of compact luxury pontoons, shipping around 10 percent of its boats with a Torqeedo. In 2013, Torqeedo unveiled the Deep Blue outboard, which produces 80 hp and won many accolades, including the coveted NMMA Innovation Award at the Miami Boat Show. Last summer I was lucky to be one of two U.S. marine journalists to be invited to Germany to see Torqeedo’s latest, the Deep Blue inboard, which comes in either a 40 or 80 hp configuration.


At a compact 14 inches tall and less than 20 inches wide, the new Deep Blue allows boat builders to maximize a space that is normally occupied by an engine sized for a car. To keep it small, yet more powerful and efficient, it employs a permanent-magnet-excited motor, instead of an electromagnetic motor that needs a secondary coil. Typical mechanically commutated motors have brushes that make constant sliding contact and eventually wear out; Torqeedo’s electrically commutated motors, on the other hand, create the necessary alternating field via electric switching, which makes them virtually maintenance free. Deep Blue which is 98 percent efficient, is then connected to a simple direct-drive propulsion system.

While writing this, I discovered Torqeedo finalized a deal with fabled automaker BMW to use the new-for-2017 BMW lithium-ion battery that it uses in its i3 car. A marinized version of the battery will be displayed in the U.S. for the first time at the Miami Boat Show in mid-February. A single one of these will replace the previously necessary two-battery packs (still available for the 40 hp version) and is rated at an astounding 33 kWh, which is 8 kWh more than the two-battery system; plus, it is lighter (563 vs. 660 pounds), smaller and less expensive. Its nominal voltage is a whopping 360v, and it carries the same nine-year warranty. Even if you use it every day, at the end of nine years it retains 80 percent of its charging capabilities.


We tested the Deep Blue inboard on a 20-foot Designboats Tender 06e (with the older-gen batteries), and the boat was surprisingly quick. Acceleration was immediate and swift, as the boat got on plane in 2.5 seconds. Top speed was 29.2 mph at 6500 rpm, but wideopen throttle will result in a rather short day on the water, since the battery life at WOT is only about 30 minutes, even with two batteries. Throttling back to 1000 rpm provides a range of 127 miles. I found that the throttle and shift lever worked smoothly, but it felt cheap and insubstantial in my hand and could use a redesign.

The Johnson monitor used to be the weak link of the system. It showed 14 valuable tidbits of info, but the display itself was dim and difficult to read. But at the Miami sho w, consumers will learn about a new high-def display that replaces the old 5.6-inch monitor and delivers a multitude of info, including range and battery time still available at each throttle setting.

Now for the bottom line. The Deep Blue 80 inboard comes at a price of $19,999, which includes the charger, controls, 12v starter battery, motor, direct drive system and all connections. The previous-gen batteries cost $15,999 apiece, and the 80 hp model really needed at least two of them, which pushed the total cost to near $52k. With the new BMW i3 battery, that cost is reduced by $4,499. Torqeedo makes the case that if you use your boat a lot, the fuel savings over nine years can put you in the black. As of now, however, most buyers are boat owners who use their vessel commercially and some deep-pocketed “green” boaters. But automakers are aggressively investing in electric/hybrid technology, so the price of electric should drop enough to make it more of a mainstream option.