William Dobelle wasn't the average fisherman when he was a student at The Johns Hopkins University. While he was running his own company, Specimens Unlimited, he made forays into the North Pacific for sperm-whale hearts and Alaskan king crab testicles, selling his exotica to museums and laboratories for scientific research. "I developed some empathy for the problems of the commercial waterman," he says.

Bioengineer Dobelle is back on the water again, some 20 years later, as president of The Logical Boat Co., of Amityville, N.Y. Although this time the ocean is just a sidelight -- Dobelle is chairman of the Institute for Artificial Organs, in New York City, where he designs neurological prostheses -- his company is selling an unusual 46-foot catamaran that he says can be twice as fuel efficient as a monohull boat.

Dobelle's dual-hull vessel, which took seven years and $2 million to develop, has extremely wide hulls that enable it to handle heavy loads -- lots of fish, for example. About the size of two house trailers, the Logical Boat offers the interior space of vessels twice its size.

The company's line includes commercial fishing, sportfishing, recreational sail, recreational power, and charter models. The basic boat costs from $250,000 to $350,000, depending on how it is outfitted; customers can order a mess room for commercial fishing or bedrooms and a study for leisure vessels.

Dobelle's boat may be logical, but its fat hulls make it a bit peculiar-looking. That might slow sales a bit. "I'm sure there are plenty of fishing people and pleasure people who won't want this thing, because it's different," says John H. Deknatel, president of C. Raymond Hunt Associates Inc., a Boston naval-architecture firm.

But Dobelle isn't worried. The first boats have been delivered and there have been hundreds of inquiries from around the world. Designing a boat isn't as exciting as hunting for sperm-whale hearts. But then again, sperm-whale hearts didn't fetch $350,000.