On the wall of the office, a color photo shows a catamaran with a tanned, laughing, three-man crew skimming over crystal blue waters toward a tropical island.

Outside a cold wind howls through this port city, rushing over the surface of the icy Hester River. The Hamburg weather makes the photos on the office walls even more appealing.

There is one of a crescent-shaped Tahitian island embracing a quiet lagoon, another of a golden stretch of beach in the New Hebrides.

Aerial and offshore views picture islands off the Pacific Northwest, Canada, Australia, France, Sweden, Panama, Greece and elsewhere -- one a scant hour's trip from New York City.

"Those islands are all for sale," said Farhad Vladi. He is a partner in the firm of Boehm and Vladi, which says it is the only real estate firm that deals exclusively in the sale of islands.

"Go ahead and pick one," he said, laughing. "You might find the island of your dreams."

Vladi, 33, the son of a Persian father and a German mother, and his partner, Rene Boehm, 35, are not dream merchants, peddling Shangri-las to wealthy dropouts.

The vast majority of the Boehm and Vladi clients are hard-headed businessmen or investors, more interested in making money than in the pleasures of some enchanted island. Even those buyers touched by the romance of owning an island. Buy them only as temporary havens from the travails of civilization.

"None of our clients are complete escapists," Vladi said, his soft voice barely audible above the wind. "People can't live on an island all the time. We don't even try to sell islands that are far from the mainland."

His sales list is limited to islands no farther than 10 miles from the mainland. The ideal distance, he said, is only a few hundred yards or closer to the mainland or a larger inhabited island.

The partners have made more than 100 sales since they went into the business 10 years ago. Some involved more than one island -- one sale involved 36 islands off the Swedish coast, and another was for five islands in Canada.

The smallest island sold was two acres, the largest 10,000 acres. Prices ranged from $20,000 to $2.5 million. Their commissions total $4 million a year, they said.

The buyers -- mainly German, but there have been a few Texans -- all into three categories:

The "pure" investors, who usually are not even interested in visiting their islands. They simply buy on the basis of economic surveys, photos and maps in the expectation that the value will increase -- as it almost surely will -- and then they sell at a profit.

The investor-developers, about half of whom actually visit the islands they intend to buy, planning either to subdivide them and sell plots to other purchasers or develop them as resorts.

The third type of buyers are those, Vladi said, "who want to enjoy an island for themselves and their friends."

"These buyers," he added, "usually build one or two houses on the islands as vacation retreats -- not as permanent residences."

Among Boehm and Vladi's current offerings is a 32-acre island in French Polynesia for $500,000. The company's prospectus described the island as a palmdotted paradise with a beach of light coral sand and a safe anchorage in a reef-fringed lagoon. Located less than a mile from the larger island of Raiates, the only existing improvements on the island are a small house, a copra dryer for making coconut oil, a jetty and a garage with a Land Rover. It also has a small coconut plantation that provides an annual net income of $1,500.

"Of course," Vladi said, "There are many more islands that are available for sale if the price is right, but not nearly as many as people think."

In all, he estimated, there are only 1,000 islands around the world that could be considered as acceptable for sale. These would include islands that have an adequate supply of fresh water, whether through the use of cisterns, wells or expensive desalination plants, and other features that would make them safe and practical for human habitation.

"But if you don't care about such amenities," he added, "I'd say there are about 10,000 islands in all that could go into private ownership."

As part of it lure to purchasers, however, the company emphasizes that the number of islands available for sale is dwindling. Dealing only in the sale of whole islands, it notes that many of the private silands are subdivided. "And once that happens," Vladi said. "It is almost impossible for purchasers to buy the whole island."