Russian President Vladimir Putin has sacked the head of the navy, Admiral Vladimir Kuroyedov, a month after a mini-submarine accident.
Putin said the new navy chief faced "difficult tasks"
Seven Russian sailors who were trapped in the vessel in the Pacific had to be rescued with help from abroad.
The crew, facing dwindling air supplies, were saved after three days.
Mr Putin did not give any reason for Mr Kuroyedov's dismissal. He named Mr Kuroyedov's deputy, Admiral Vladimir Masorin, as his replacement.
Mr Putin said that since Mr Kuroyedov had taken office in 1997, there had been progress in restoring "a significant part of the navy" and planning its development.
But he added that in the same period there had been "difficult events" and "tragedies".
Nevertheless, he said, despite all the problems and tragedies, "the main thing is that the navy is undergoing a revival".
The reason for Mr Koroyedov's dismissal is unclear, but an admiral, Eduard Baltin, told Moscow radio that it might have been linked to the former navy chief's ill health.
"He has been lying in hospital for two months, he had a complicated operation," Reuters news agency quoted him as telling Ekho Moskvy.
Russian media last month harshly criticised the handling of the latest emergency at sea.
Mr Kuroyedov was also in charge of the navy at the time of the Kursk tragedy in 2000, when 118 crew members died after their submarine sank.