Rescue operation: Director of Marine Roger Tupper and Chief Fire Officer Chow Wing-tak explain the location of the sunken tug.

A rescue operation has been launched to locate 18 crew members of a tug that collided with a ship off Lantau Island on March 22.

The Marine Department has launched a salvage operation to recover the sunken tug which is lying upside down on the seabed at a depth of 35 metres.

Director of Marine Roger Tupper said today a salvage operator will move the wreck to shallow water to allow a more thorough search as there is a chance the crew are still alive trapped inside the Ukrainian-registered tug.

Hong Kong Island, Islands & Marine Commander Chief Fire Officer Chow Wing-tak said divers inspecting the wreck have so far seen no signs of life. However, their efforts have been hindered by poor visibility due to silt and the rapid current in the area.

An investigation has been launched find the cause of accident which happened about 9pm yesterday. The tug collided with a Mainland-registered bulk carrier and sank rapidly. Seven crew were rescued and sent to Tuen Mun Hospital.