Narragansett-based FarSounder Inc. has been generating a buzz in Rhode Island's entrepreneurial community this year with the development of its three-dimensional sonar system. Now the startup is giving outsiders a glimpse of its progress.

On a former Navy training boat, rented from the University of Rhode Island, FarSounder officials earlier this month gave prospective investors and government officials an up-close look at FarSounder 200, the startup firm's first product, set for launch this spring. Under blue skies, in calm waters off Quonset Point in Narragansett Bay, onlookers huddled around a computer monitor in the boat's cabin for a glimpse of the prototype technology.

The system uses color-coded 3-D images as a navigational tool to give mariners a view below the waters ahead, allowing them to avoid everything from sandbars and rocks to whales.

As the boat approached a shallow patch called Boiler Awash, roughly 100 meters off Hope Island, the screen's 3-D image reflected a topographical image of the sea floor. Deep blue tones gave way to piles of green, yellow, orange and finally red shelves indicating a shallow spot that would ground most boats.

"Boats run aground here every year," said Matt Zimmerman, FarSounder's co-founder and the firm's vice president of engineering. "Just by looking out over the water, there's really no way of knowing how shallow it gets."

Last spring FarSounder's business plan emerged from a field of about 80 competitors to win the $50,000 Rhode Island Business Plan Competition. The startup has been supported by private investors and seed money from the state's Slater Fund, although it has yet to receive an initial round of venture funding.

Still, FarSounder officials say they hope to launch the company's first product in February at the Miami Boat Show. The initial target markets: mega-yachts and smaller commercial vessels, such as tug boat operators or oil rig service vessels. Zimmerman says those customers are looking to protect their investments - and are likely to be unfazed by the system's $75,000 price tag.

But Zimmerman envisions eventually selling to commercial fishing vessels, large cargo ships and cruise ships. Before it gets to that point, however, the product - already on its 20th generation of software and fifth version of hardware - needs further tweaking.

FarSounder's two software developers - both URI graduates - are incessantly enhancing the software. The 3-D user interface was added in the last few months. And images now refresh every three to four seconds, down from three hours.

But Zimmerman and co-founder James Miller, a URI professor, still have big plans for the system. They want to add a nautical chart overlay as well as an audio or visual alarm system, which would alert the navigator to imminent dangers in the water. And they want to boost the range of the system to two miles, which would make the technology viable for large vessels such as cruise and cargo ships.

But perhaps the biggest step for the technology, Zimmerman said, is adding classification - actually identifying in-water objects that lie ahead.

"Right now we're going to tell you where things are, but we're not so good at telling you what it is," Zimmerman said.

Classification could open opportunities in commercial fishing and the military, Zimmerman said. Is that a school of swordfish or tuna in front of the boat? An underwater mine or a harmless submerged shipping container?

Zimmerman said FarSounder has a development agreement with the Naval Undersea Warfare Center to help add classification capabilities.

FarSounder hired former venture capitalist David Wood as its chief executive officer in January, though he left after just four months. Zimmerman said Wood "wasn't the right match" for the firm, which has since hired Zimmerman's mother, Cheryl Zimmerman, as its CEO. She is a mechanical engineer who has a strong entrepreneurial track record, Matt Zimmerman said.