Cold enough to freeze the muddy waters of the Kuskokwim River into a wide open, frosty-white freeway.

Van Valin is the Bethel area manager for Lynden Inc. and its subsidiary, Alaska Hovercraft Ventures. The company is gearing up for its seventh winter of hauling mail, freight and passengers to and from eight small riverside villages -- in unique fashion.

"The Craft" -- as they call their 70-foot, 30-ton British-built AP 1-88 hovercraft -- has evolved from being a curiosity into a profitable and reliable operation, Van Valin said.

Before long, they will shut down again for the big chill.

"We need the ice to be about 18 inches thick, then we're on the road again," he said. "It's not because the hovercraft can't operate (during freezeup), but it would break the ice," and cause hazards for villagers using snowmachines during early winter.

The annual layover periods haven't hurt the bottom line. "It's making money," Van Valin said.

The usual cargo for the service, more than 1,500 tons a year, is fourth-class and "bypass" mail. That includes groceries, dry goods and other supplies sent directly from stores to bush residents without going through a post office. The service also hauls "all the stuff that people have a hard time fitting into a small airplane," Van Valin said.

"Usually we get the oddball freight, oddball sizes," he said. "We can handle fairly large stuff. Mattresses, beds, couches, coffins. We'll haul snowmachines." One freight run a while ago included four 30-foot long telephone poles strapped to the side of the vessel, he said.

The vessel also has proved itself as a riverborne ambulance, being used for more than a dozen emergency medivac missions to villages. "When the weather was down, or the airport runways were not useable," the vessel can get through the inclement conditions, Van Valin said.

When the service began in July 1997, concerns were raised by villagers that the high-speed craft could cause environmental problems by frightening birds and disrupting fish spawning beds.

According to a summary of a three-year ecological monitoring program conducted for the Postal Service by the U.S. Department of Transportation, "the hovercraft had an insignificant impact on subsistence gathering of waterfowl and fish."

Concerns also were raised about noise pollution from the craft. It is powered by four diesel engines that pump out a total of 1,780 horsepower. Two of the engines provide lift, and the other two push the craft along on a three-foot cushion of air at speeds of 30 knots or higher.

That doesn't bother Jack Wassillie, assistant manager at the Napaskiak Inc. Village Store. He said they welcome "the Craft" as it arrives at the village along the Johnson River about seven miles southwest of Bethel.

"I don't know. I've never heard anybody complain about noise," Wassillie said. He said the hovercraft generally make two visits a week and they are pleased with the mail and passenger service. "It's a lot faster and a lot cheaper," than using aircraft, he said.

Fifty miles upriver from Bethel, Middy Peter helps run the Tuluksak Native Store. He said the village of about 500 people gets most of its groceries via hovercraft.

"The stuff gets here with less damage. We have fewer problems now that we are going through the hovercraft," he said. Peter said it also provides much more economical passenger service in the region, compared to the cost of flying.

Van Valin said it took a couple of years, and a lot of cold-weather modifications to the air ducting and engine cooling systems to make the hovercraft more efficient in a sub-arctic environment. "It took trial and error. A lot of trial and a lot of error," he said.

"We've been stuck out for the night only once in the past six years," he said. "It will come back on only two engines, but they've got to be the right engines. With one lifting and one pushing, you can bring it back."

Van Valin said, as far as he knows, the AP 1-88 based in Bethel and a sister ship in Anchorage are the only two of their kind in the country certified for commercial and passenger use by the U.S. Coast Guard.

Lynden's current contract with the postal service was signed in 2000, and runs through June of 2006. Steve Deaton, Network Operations Specialist at the Postal Service headquarters in Anchorage, said they are pleased with how things are working out.

"We are entirely satisfied with it," Deaton said. "From a service standpoint, it's been more reliable than air, because it can go during times when aircraft can't. And it takes larger volumes in to the customers, so the shipment doesn't have to be broken up."

Dave Haugen, vice president of Lynden Inc. in Anchorage, said Alaska Hovercraft Ventures is a joint venture with Cook Inlet Region Inc., with Lynden owning 60 percent of the operation and CIRI controlling 40 percent.

"It's something that we consider to be a success, and it's now developing into a commercial operation. It's zipping right along," Haugen said.

The Bethel-based craft can haul a total of 12,500 pounds of cargo. Alaska Hovercraft Ventures also owns and operates 15 larger, LACV-30 model hovercraft, capable of hauling 30-ton loads, he said.

"They're scattered all over the place," Haugen said. "We've got a half dozen of those in the Lower 48, some in Anchorage, two over in Valdez and two up in Prudhoe Bay."

The heavy lifters have turbocharged engines and use 260 gallons of fuel per hour, compared to 60 gallons per hour for the AP 1-88 model in Bethel.

Haugen said the company is always open to expanding the air-cushion vehicle business in Alaska, should the right combination of factors come together.

"If another opportunity presents itself, we would certainly take a look at that," he said.