LUBEC, Maine — The U.S. Coast Guard fielded comments and suggestions Monday evening from Cobscook Bay fishermen and others attending a public hearing in Lubec to discuss a proposal to test five experimental underwater turbines.

Portland-based Ocean Renewable Power Co. has been engineering and field-testing its turbine designs in waters off Eastport since 2004. It now wants to submerge five turbines in 82 feet of water with a 61-acre footprint between Goose Island and Grove Point.

Each of the units is 98 feet wide and would extend 31 feet above the ocean floor. If an eight-year pilot project permit is approved by the Federal Energy Regulatory Commission, placement of the first of the units would happen sometime next year.

The Coast Guard has determined that the submerged turbines would not pose a hazard to vessels at the surface, but would pose a “significant” hazard to underwater activities such as dredging, dragging, anchoring and diving. Lt. Megan Drewinak, chief of the region’s Waterways Management Division, said those hazards include entanglement of fishing gear and possible electrocution through contact with underwater cables that will deliver the electricity generated by the turbines to the shoreline.

“Subsurface, it’s a hazardous condition,” she said. “In terms of innocent transit, it’s not.”

Many of Monday’s public comments focused on how best to mark the area should FERC approve the project, so that its location is made clear to mariners who are unaware of the underwater test bed. ORPC has offered to supply and maintain four large, lighted buoys that would mark the corners of the rectangular test area.

Chief Warrant Officer Bob Albert, the region’s aids to navigation officer, said the Coast Guard prefers not to add buoys to navigable waterways, as they represent hazards. “But this is a unique project,” he said. “It’s a project that requires that it can take advantage of the natural resources that the currents and tides here provide.”

Among the 35 people attending, Bob Peacock, who captains a pilot boat that ferries large ships into and out of the Port of Eastport, was one of those who made comments Monday.

“I would suggest that it be marked as an area to be avoided for underwater activities,” he said. “These fishermen here tonight are professionals, and I’m sure nobody in this room wants to get entangled. But there’s no question that you have to have it marked clearly so that everybody knows where this area is. And you need good-sized buoys, given the currents and tides.”

Albert said he sees a potential hazard in draggers not familiar with Cobscook Bay getting in the test bed area and becoming entangled with a submerged turbine.

Monday evening’s hearing at Lubec Consolidated School was the first of two being staged by the Coast Guard. More comments will be solicited on Tuesday during a similar presentation to be held in Eastport. That public hearing begins at noon at the Friends of the Boat School on Deep Cove Road.