In a warehouse in Concord, a startup is quietly building what it calls the first emissions-free, wakeless water shuttle in the U.S. — a 40-passenger, all-electric ferry aiming to launch on the Charles River sometime in 2026, though no firm date has been set and permitting isn't finished yet.

The planned route runs from Watertown Square to Beacon Hill, with 11 stops on both the Boston and Cambridge sides of the river — a route that's shifted since 2024, when the company originally planned to end at TD Garden. The full Watertown-to-Hatch Shell trip is estimated at about 67 minutes, while shorter hops, like Kenmore to Back Bay, could take as little as three. Fares were projected at $15 to $18 per trip back in 2024, though current pricing hasn't been announced.

The Charles runs as shallow as 17 inches in spots, so the ferry's shallow-draft design — developed with the Coast Guard — lets it operate in just 16 inches of water. It's also built to glide past rowers and kayakers without creating a wake.

"We've probably passed by 80 cars in the last couple of minutes," co-founder Drew Rollert said during a 2024 interview on the river. "How many boats have you seen? None. Zero. It's just us and a couple of ducks."

Rollert's Uber canceled, the MBTA bus ran late, and while walking across a bridge afterward, he noticed an unused dock and started looking into river transit. He co-founded Wada Hoppah — a phonetic nod to a Boston accent for "water hopper" — with Will Congram, a former Community Rowing coach and Northeastern rower. The company claims a single shuttle could pull 400 to 640 cars off area roads daily, though it hasn't published the methodology behind that number.

The ferry is being built in Concord, though the company hasn't disclosed the exact facility. Since 2024, Wada Hoppah has been in talks with Newton, Watertown, Cambridge, Boston, the state Department of Conservation and Recreation, and several river advocacy groups over dock access and regulatory approval. No hearing date or milestone has been announced yet. Updates are posted at wadahoppah.com.