Firdosh Moghul, an executive officer of Sankush, was preparing for some exercises when a maintenance officer got washed away into the sea by a rough wave, officials said.
"Firdosh rushed to rescue the officer but got pulled into the sea himself. Coast Guard officials were immediately rushed to the spot. While they managed to save the maintenance officer, we lost Firdosh," defence PRO M Nambiar said.
Five Naval officers fell off the submarine around 8.30 am. Four officers were rescued by a helicopter and were admitted to a hospital in a critical condition.