Hong Kong marine policemen prepare for another search attempt for the seafarers of the Ukrainian tugboat Neftegaz 67 yesterday. The vessel sank Saturday night after colliding with another ship. Director of Marine Roger Tupper said there is little hope of survival for the 18 sailors trapped inside. CNS

The biggest floating derrick in Asia, the Hua Tian Long, will be used to salvage the sunken tugboat near Lantau Island with 18 Ukrainian sailors inside, rescue officials said yesterday.

The decision to use the Hua Tian Long came as rescue efforts remained futile. The Neftegaz 67 tugboat overturned and sank on Saturday after colliding with the Yao Hai, a Chinese cargo ship. No one was injured aboard the Yao Hai, and it suffered only bow damage.

The derrick - basically a large, floating crane - was used for the salvage of the Song Dynasty merchant vessel Nanhai No. 1, which carried porcelain and rare antiques. Guangzhou Salvage Bureau Senior Engineer Zhang Jianwen said the Hua Tian Long will arrive in Hong Kong as early as Friday.

The bureau director and other officials conducted a site visit yesterday and concluded that the conditions in the area were suitable for the derrick operation.

Of the 25 sailors aboard the 264-foot-long Ukrainian ship, only seven were rescued. Roger Tupper, director of marine for the Hong Kong Marine Department, said that the survival chances for the 18 sailors were slim. He said the water temperature is 17 degrees, and the average man can withstand that for only 12 hours. He also said rescuers knocked on the ship's exterior but no response could be heard.

Divers will continue using steel ropes to stabilize the tugboat before the arrival of the Hua Tian Long, Zhang said.

The salvage operation is expected to take about six hours. Its difficulty is enhanced by strong currents, he said.

"Besides, the information about the tugboat is unclear," Zhang said. "Our experts believe that the tugboat weighs between 2,500 and 2,600 tons, but there are also suggestions that it might weigh just 1,700 tons. The weight of the tugboat will determine how many steel ropes should be used."

Another proposed option was to drag the tugboat into shallower water, but Hong Kong Chief Fire Officer Chow Wing-tak told reporters it wasn't possible because the towboat was stuck in the seabed.

The diving time of the rescuers was extended from 20 to 25 minutes with the use of a decompressor provided by mainland authorities, but difficulties still remained and the entrance of the ship's hold couldn't be found.

"The current is still very strong and visibility is very low. The divers can only feel their way around," he said.

But he stressed that the efforts will continue until all of the 18 sailors are found.

A fireman providing backup help to the divers said the operation was the most difficult one he has assisted in.

"The ships in the area are constantly being moved by the water because of the strong current," he said. "In other operations, the backup ship can easily approach the damaged ship. That isn't possible now because the tugboat is stuck underwater."

The Ukrainian ambassador to China, Serhiy Kamyshev, also arrived to observe the efforts. He said that a group of 20 marine and rescue experts from the Ukraine will arrive today.

He added that Ukrainian President Viktor Yushchenko was thankful for the rescue efforts made by the Hong Kong government.

(HK Edition 03/25/2008 page1)