The biggest challenge for the cruise industry over the next decade may be the cultural one.

As cruise lines peer into the future, their prospects more than ever depend on countries where cruising is unfamiliar as a vacation option. The good news is that few people outside of North America have been on a cruise, meaning there’s plenty of potential for growth. But in many countries it’s still too early to tell if cruising is going to be a long-term hit with vacationers.

Cruising is largely an Anglo-American vacation. When the number of people who have cruised is measured against total population in various countries, the top four markets are the U.S., the United Kingdom, Australia and Canada. In all of these countries, more than 2% of the population has cruised.

Germans also appear to love to cruise.  Some of Carnival Corp.’s best performing ships sail for German brands.  The number of cruisers from Germany could overtake the total from the U.K. within five years, CLIA President Christine Duffy recently forecast.

Next comes Italy, home to Costa Cruises and MSC Cruises, but it produces only 4% of the world’s passengers, notes a report from Stivel Nicholas analyst Steven Wieczynski. By comparison, according to Stivel Nicholas, Germany accounts for 6% of global passengers, and North America accounts for 75%.

“While passenger counts from the other major European markets, including Italy, Spain and France, continue to grow, overall market penetration remains subdued,” he wrote in a recent report.

In Asia, many Japanese travel abroad, but relatively few go cruising. Although Princess Cruises is taking another stab at developing the market in Japan, some cruise executives say the idea of a cruise hasn’t taken root in that country.At a recent cruise conference in Hong Kong, Carnival Asia CEO Pier Luigi Foschi said the penetration rate for cruises in Japan is 0.08%, compared with about 3.4% in the U.S. In China, it is even lower, at 0.04%.

To their credit, Carnival and other cruise companies are investing significant sums to experiment in Asia to figure out what kind of cruise might appeal to residents there.

The potential for gaining even a small part of the 80 million Chinese who traveled abroad last year is too tempting for the cruise lines to pass up. The challenge will be creating a cruise for the non-Anglo world that translates well into the local vacation culture.