ROCKLAND – In a pinch, you probably could sail one of the floats Harbor Technologies builds out of port and into the open seas.

But that’s not how Martin Grimnes, president of the Brunswick company, is marketing the floats.

Instead, he said compared to their wooden counterparts, the floats, made from Fiberglas and polyester resin, are lighter and easier to haul into and out of the water, are more stable in the water and will last many years longer.

So far, Grimnes said, his company has sold its floats to the city of Bath, Isle au Haut and others in Maine. A developer proposing a marina at the former Stinson Seafood plant in Belfast is considering using the floats, he said. Grimnes was at the Maine Boats & Harbors Show on Rockland’s waterfront on Friday hoping to drum up more sales.

The float is much like a catamaran hull. The twin-hull design is favored by more and more boat builders for its stability and speed. Grimnes had the float version, which he calls a “cat dock,” designed by a naval architect.

“Nobody makes them that we have seen worldwide,” he said.

The Fiberglas hulls, an inch and a quarter thick, are pitched much like the popular “party” or “platform” boats used on inland waters. That profile makes it easy for the floats to be towed around a harbor, Grimnes said.

The shape and weight of the floats, about one-third the weight of a like-sized wooden float, also make it easy to drag them up on shore, he said. The floats delivered to Isle au Haut from Stonington were towed at 10 knots, Grimnes said, while wooden floats might be towed at 3 knots.

The 12-foot-by-24-foot model weighs 2,700 pounds, compared to about 7,000 pounds for a like-sized wooden float. Wooden floats gain weight after they have been in the water for a time, Grimnes said.

The deck that spans the two hulls is also made of Fiberglas and is coated with nonskid epoxy paint. A tie-up rail around the perimeter is made from a composite material similar to synthetic decking used on houses.

As light as the floats are, their displacement makes them more stable than a wooden float. Stepping from a wooden float onto the 12-foot-by-24-foot model Grimnes was displaying on Rockland’s harbor, the cat dock barely moved.

The company tested a 12-foot-by-24-foot version and found it would carry 20,000 pounds while maintaining 1 foot of freeboard.

Harbor Technologies sells its cat floats for about 15 percent more than a comparable wooden float. The 12-foot-by-24-foot float demonstrated in Rockland was sold to Bath for $8,000, Grimnes said.

The cat docks can be built at 8 foot by 20 foot, 5 foot by 20 foot, and 5 foot by 30 foot.

Perhaps the strongest selling point for the cat docks, he said, are that they may last 30 years or more, compared to a 15- to 18-year life span on a wooden float. Fiberglas hulls on boats built in the 1960s are still going strong, he said.

Grimnes said his company also is beginning to sell pilings made from composite material, which will resist the damage caused in many Maine harbors by the shipworm. Harbor Technologies recently landed a $250,000 grant from the Maine Technology Institute to further develop the pilings.

For more information, visit www.harbortech.us.