The two navies reportedly exchanged humanitarian rescue techniques including locating distressed submarines, mating rescue equipment and decompression treatment procedures.

Submarine rescue concerns crew lives regardless of flag and is an area where navies cooperate relatively often.

Beijing maintained that the exercise is routine cooperation aimed at no third party.

Neighbors continue to watch the drill area and participating forces; analysts note rescue-subject exchanges can help standardize responses to accidents at sea.

The exercise continues on schedule, and Sinophone Bridge Times reports its progress on the facts.