Good news for travelers: Singapore, a gateway to vacations in Southeast Asia, and one of my favorite home ports for boarding cruise ships, is anticipating an expanded fleet of big, modern vessels. They will be based at new and enhanced marinas, built here at a cost of half a billion dollars.

“No doubt about it, we’re going to have a cruising boom during the next four years,” said Bob Guy, Singapore’s managing director for Destination Asia. An experienced tour operator with a wealth of understanding about the cruise business, he predicts 8-12 ships will be based in Singapore by 2016. Today, most North American ships either stop here for a short visit or are floating between Singapore and Sydney to the south or Singapore and Hong Kong to the north.

Heavy selling these days is aimed at Asians, as cruise lines see a profitable future in drawing new cruisers from India, South Korea and China, where more than 100 million new people a year are reported to have enough disposable income to vacation on a cruise ship.

Among cruise companies from North America operating in Singapore, Royal Caribbean is the leader, including ships from its Celebrity and Azamara brands. Regional director Kelvin Tan said that in 2006 he was Royal Caribbean’s only employee in this part of the world; now there are about 200. Carnival Corp. recently opened a headquarters here for its brands, especially Costa; Princess also is expanding its offices.

For North Americans and Asians, Singapore seems an ideal hub for round-trip cruises of 7-12 days. Look at a map: Within reach are Malaysia, Thailand, Myanmar (Burma), Cambodia, Vietnam, and the many islands of Indonesia, including Borneo and Bali.

One major problem: While smaller ships from lines such as Azamara and Seabourn can dock in ports near many of these prime destinations, larger ships cannot. In Southeast Asia, ports need to provide deeper water access, piers and a decent-looking dock.

“There are some industrial ports,” said Guy, “but who wants to get off a fancy cruise ship at an oil-soaked pier built for containers?” As many as 20 ports in the region need to be re-done, he estimated. “Where is the money coming from to build ports for modern ships?” Cruise lines may need to make some big investments, he said.

Cruising is not new to Singapore, but most voyages that originate here either are cruises of two weeks or more or are short and without destination. The big player is Star Cruises of Hong Kong. Star’s ships are designed for gambling and eating, and not much sleeping. “They are packed for a party at all hours,” said Guy, “and so gaudy they make Carnival ships look like a hospital.”

“The tough job, in selling cruises to Asians,” said Tan of Royal Caribbean, “is trying to undo the image of what a cruise is — most here have been on cruises to nowhere, or two-day gaming and shopping trips.”

Asia, Tan said, is for the long haul. Cruise lines “may not get in if they wait, as berths are limited. The market is booming. Asia is booming.”

Another big question that could affect the number and size of ships deployed here: Will North Americans and Asians mix well, on the same ship?

Local tourism officials said they didn’t think that would be a good idea. “You can’t put everyone in Asia on the same ship with North Americans,” said one official, citing “too many cultural differences” in manner, sophistication, and vacation styles.