Type 646 water tanker (AWT) is a type of naval

auxiliary ship An auxiliary ship is a naval ship designed to support combatant ships and other naval operations. Auxiliary ships are not primary combatant vessels, though they may have some limited combat capacity, usually for purposes of self-defense. Auxil ...

currently in service with the People's Liberation Army Navy (PLAN). Type 646 series ships in PLAN service are designated by a combination of two Chinese characters followed by three-digit number. The second Chinese character is Shui (水), meaning water, because these ships are classified either as oil and water tankers. The first Chinese character denotes which fleet the ship is service with, with East (Dong, 东) for

East Sea Fleet The Eastern Theater Command Navy (), or East Sea Fleet (ESF; ), is one of the three fleets of the People's Liberation Army Navy, operating in the East China Sea under the Eastern Theater Command. It was the first naval force formed by the Peop ...

, North (Bei, 北) for North Sea Fleet, and South (Nan, 南) for

South Sea Fleet The Southern Theater Command Navy (), or the South Sea Fleet (SSF; ) is one of the three fleets of the Chinese People's Liberation Army Navy, operating in the South China Sea under the Southern Theater Command. It is headquartered in Zhanjiang, ...

. However, the pennant numbers may have changed due to the change of Chinese naval ships naming convention. Two have been identified as still in active service as mid 2015:

References

{{Ship classes of the Chinese Navy, state=uncollapsed Auxiliary ships of the People's Liberation Army Navy