The typical domains of wireless networks are college campuses, major airports, high-end hotels, trendy coffee shops and tech-heavy neighborhoods. But Forrest C. "Woody" Wheat sees a new horizon for this increasingly popular technology: the near-shore waters of the American coast.

Wheat, whose Reston-based firm has been selling high-speed wireless service for three months after a year of building a network, said he hopes to expand it for boaters using "every little estuary" along the U.S. coast. Wheat sees maritime service as his way to carve a niche in the market for the technology known as WiFi, a system that makes high-speed Internet connections from a laptop as portable as a call from a cell phone. He is among an expanding fleet of competitors looking to capitalize on the technology.

Those who sell WiFi service still face technical and financial challenges, and few firms have managed to profit from selling the service. But analysts and market watchers expect consumers to embrace the technology in greater numbers, even as the rest of the telecommunications industry struggles to stay afloat.

A few companies like Wheat's offer commercial WiFi service in the Washington region, and major telecommunications companies, such as T-Mobile and Sprint PCS Group, have invested in companies that are beginning to market similar services. AT&T Corp., IBM Corp. and Intel Corp. formed Cometa Networks Inc. just over a month ago to sell WiFi service on a national scale.

Cometa plans to build networks in the 50 largest U.S. cities this year and to blanket metropolitan areas -- including Washington and its suburbs -- with wireless nodes so they will be easy to find. It hopes to sell its service to major national hotel and restaurant chains

Wheat Wireless Services, through its TeleSea division, offers a $500 monthly plan aimed at cruise ships and yachts whose crews and passengers will be able to surf the Web, make appointments, or get up-to-the minute information on weather, wind current and water depth, said Wheat, president and chief executive of the private firm, which he owns with his wife, Linda.

Wheat said TeleSea's signals -- unlike most others, which are limited to a range of several hundred feet -- can reach as far as 30 miles from the coast because of the design of its radio towers. So far, Wheat has invested less than $5 million to cover the coast from Baltimore to the Florida Keys, Puget Sound, San Francisco Bay, Long Island Sound, Southern California and Hawaii.

"Our goal is to connect the entire coastal U.S." piece by piece, Wheat said.

Until now, the people embracing WiFi have been a relatively small number of technophiles. Most people are unfamiliar with how to use the technology, and coverage is still spotty.

The number of WiFi cards or access points manufactured in the United States grew from about 3 million units in 2000 to about 10 million in 2002, according to the Yankee Group. In the next five years, the market could grow 30 percent a year, said Sarah Kim, an analyst with the market research firm.

WiFi, known technically as 802.11b, has populist appeal because it is simple and cheap. It requires only that a user plug an $80 card into a laptop and stay within range of a device sending a signal. Because the wireless signal travels on a licensed airwave spectrum -- the same segment of airwaves that cordless phones and garage-door openers use -- it doesn't require regulatory approval.

The technology has skeptics.

The Defense Department says expanded use of WiFi could interfere with military radar systems. It has proposed limiting its use in certain ranges of airwaves so there will be no risk of it interfering with its radar. With the increasing popularity of wireless devices, some companies are proposing to use additional radio frequencies to transmit signals, but that could hurt homeland security interests, said Steven Price, deputy assistant secretary of defense. Last month, the Defense Department requested that an international body limit WiFi's use in the 5-gigahertz range; the proposal will be considered by the World Radiocommunication Conference in June, he said.

"We have no doubt that wireless Internet and wireless broadband has a military as well as commercial benefit," Price said. "We met with Microsoft and Intel and many other companies involved in the wireless Internet, and the question is whether we can find a solution that doesn't degrade military capabilities."

Most of the WiFi market is controlled by upstarts such as Wheat's and Oneder LLC, a Baltimore firm that plans to start offering service in Silver Spring early this year. The larger players include T-Mobile, which bought MobileStar Network Corp. out of bankruptcy in 2001; Wayport Inc.; and Boingo Wireless Inc., owned in part by Sprint PCS.

Since Wheat Wireless began service in September, it has signed two casino cruise line customers, which plan to use their wireless connections to verify gamblers' credit, receive safety alerts, and provide e-mail and Internet services to guests.

"I'm a little tech-crazy. I'm connected. Everything I do is connected," said Wheat, who spent two decades setting up communications systems for the Navy and an additional 17 years running a company that established military communications systems under subcontract to AT&T. Wheat said he gets frustrated when he can't find a connection from his network when he's sitting in his SUV parked at a dock. He said he is banking that others like him will be willing to pay for the advantage of having connectivity anywhere, and that Cometa Networks won't edge him out of the market.

"We have engineered it before all the big hitters, although those guys have all the money in the world to get it done," he said. "They wouldn't be here if there wasn't money to be made. We've gotten here early."

Gerald H. Nesbit, left, an assistant vice president for TeleSea, and Forrest C. Wheat, the president and CEO of Wheat Wireless. Wheat, hoping for an early-mover advantage, says his goal is to wirelessly connect "the entire coastal U.S." piece by piece.With TeleSea's wireless service, based on WiFi technology, boats can get up-to-the-minute information on weather and the depth of water. Analysts say WiFi may be a rare telecom industry bright spot.