HAIKOU - A cruise ship has returned from the Xisha Islands after investigating possible routes for developing tourism among islands in the South China Sea, the cruise operator said Tuesday.

The Japan-imported Yexiang Gongzhu, or Scent of Princess Coconut, docked at a port in Sanya, a city in South China's island province of Hainan, on Monday after a three-day voyage to the northern shoals of the Xisha Islands, said Zhou Naijun, an official with Hainan Strait Shipping Co, Ltd, the cruise operator.

Zhou said the company would fine-tune Xisha cruise tourism plans based on information collected during the trial sail. But he said there is still no timetable for officially launching the cruise plans.

Officials with the Hainan provincial government said they are drafting plans to develop tourism on the Xisha Islands, a chain of islands scattered along the western part of the South China Sea. Hainan Strait Shipping has been issued a license to operate the Haikou-Sanya-North Xisha route.

Huang Peng, an official with the provincial transportation bureau, said that in the initial stage of tourism development, cruise ships will be allowed to sail to Yongxing Island but tourists will have to stay on board.

"They will tour around the northern shoals of Xisha, enjoying the awesome views and the blue sea, before returning to Hainan," Huang said. "For the next stage, we will build bigger ships and make other improvements to meet the demands of high-end customers."

The Scent of Princess Coconut, measuring 140 meters long and 20 meters wide, has been serving as a deluxe passenger and cargo ferry between south China ports since 1999. In order to operate the Xisha cruise route, it has been refitted with enhanced capabilities for withstanding high winds on the rough South China Sea.

The Xisha route spans a distance of about 180 sea miles, or about a 12-hour boat ride, and a round-trip cruise takes about two days, Zhou said.

Over the years, China has repeatedly reiterated its indisputable sovereignty over the Xisha Islands and adjacent waters. China's State Council said in a regulation issued in late 2009 that the government would work to "actively, prudently and neatly" open the Xisha Islands to tourism.

Huang said Xisha tourism development is "very important" because it is a declaration of sovereignty over the islands on the South China Sea that have been a part of Chinese territory since ancient times.

He said tourism development in the area would also signal that the government of Hainan is exercising effective administration over the islands.