China has become the world's second-largest market for cruise travel, according to industry reports.

Since Italian cruise liner Costa Cruises came to China in 2006, annual growth for the cruise tourism market has exceeded 40 percent. By 2030, China will become the world's largest cruise market, with 8 to 10 million customers each year, according to figures by the Shanghai International Shipping Institute.

In 2016, more than two million people boarded cruises for overseas travel, according to the China Communications and Transportation Association.

Ten Chinese ports, including Shanghai and Guangzhou, registered 996 tours by cruise liners in 2016, up 58 percent.

Global cruise operators see great business opportunity in China, and more overseas cruises will operate in the country, said Wang Ping, deputy manager of the China district of Princess Cruises.

"There has been extremely fast growth in the Chinese market. But on the other hand, its market penetration is still low compared to North America and Australia, so there is great market potential," said Wang.

According to Ctrip.com, China's largest online travel agency, cruise customers are expected to grow by 30 percent year on year in July.

Since the beginning of this year, ports have been renovated to accommodate more cruise liners, and companies have also increased the number of ships serving the Chinese market, said Ctrip in a statement.

Cruise travel is becoming popular not only in larger cities like Shanghai, Tianjin and Guangzhou, but also in smaller cities such as Chengdu, Qingdao and Xiamen, according to Ctrip.

"There have been many bookings from third- and fourth-tier cities, and we will see more bookings from mid-western cities like Guiyang in the next three years," said Wang.

It is important to improve service for tour operators to cater to the growing needs of Chinese travellers, she said.

The Chinese tourism market has been developing rapidly as people have more money to spend.

According to a report released by the China Tourism Academy and online travel agency giant Tuniu.com, around 4.7 billion domestic, inbound and outbound tourists spent 5.5 trillion yuan (816 billion U.S. dollars) in 2016.

China's tourist spending is expected to exceed 6 trillion yuan (890 billion U.S. dollars) in 2017, it said.

China plans to raise tourism revenue to 7 trillion yuan by 2020, according to the country's five-year tourism plan (2016-2020).