Chinese naval ships join retrieval efforts for Indonesian submarine Reuters 2 hrs ago By Stanley Widianto JAKARTA, May 6 (Reuters) - Three Chinese vessels, one with a manned submersible capable of descending to 10,000 metres (32,800 ft), have arrived in Indonesian waters to help retrieve a submarine that sank and broke apart last month, killing 53 on board, an official said. Indonesian navy officials and experts have acknowledged how difficult the salvage operation will be to recover the Nanggala-402 submarine lying on the sea bed off Bali. "What's most important is lifting the biggest parts of the ship from the seabed," military spokesman Djawara H.T. Whimbo said on Thursday, adding that China would be involved in the evacuation and the lifting of the Nanggala.