Maine oyster farm launches its first electric workboat

FREEPORT — When the Heron entered the ocean for the first time Thursday afternoon, the sounds of a splashing wake and laughing crew overwhelmed the low hum of its motor. Moments earlier, as it idled along the dock, some asked if the motor was even running.

“It’s really disconcerting,” said Willy Leathers, co-founder of Maine Ocean Farms, an aquaculture company that commissioned the all-electric boat. “You’re taken aback that there’s no sound to the motor running when you’re clutching it in. … But it’s exactly the feeling we were hoping for of great performance on the boat.”

Leathers and a small crew, including project designers and advocates, puttered around the harbor for about an hour, weaving between anchored sailboats to test the craft’s speed and handling.

A project three years in the making, the Heron is among Maine’s — and the country’s — first fully electric aquaculture workboats.

“As far as I know, it’s the first fully electric aquaculture boat,” said Lia Morris, senior community development officer at the Island Institute, which helped develop and fund the boat and has advocated for similar projects for years. While a few smaller electric skiffs are being used by commercial fishermen and oyster farmers in Maine, she said the Heron marks the first electric workboat of its size.

The institute helped develop another electric boat a few years ago, but it was a small vessel with a roughly 40-horsepower engine, she said. The Heron measures about 28 feet in length and 10 feet at its widest point.

Beyond hauling oysters, the boat is intended to test and demonstrate the feasibility of similar projects, Morris said.

Its dual 120-horsepower offboard motors are powered by a pair of below-deck batteries, which together hold about 126 kilowatt-hours. And it can carry up to 4,000 pounds of gear and oysters, Leathers said. Fully loaded, the Heron can go 20-25 miles on a single charge, Leathers estimates, but that capacity will depend on factors like speed.

The Heron weighs about 9,500 pounds empty, said Patrick Fogg, designer and builder at Fogg’s Boatworks, the North Yarmouth shipbuilder that put it all together. He said the batteries alone are 1,600 pounds, and there’s another 300-400 pounds of cabling that would not exist on a gas boat.

“So you’re definitely heavier,” Fogg said. “Your batteries are probably about twice the weight of your (gas) fuel.”