Prince William was the co-pilot of a helicopter which rescued two people after a ship was hit by an "enormous wave" off the North Wales coast.
One person died and five are still missing after the Cook Islands-registered cargo carrier sank 10 miles west of the Lleyn peninsula.
The Duke of Cambridge was called into action after a mayday call at 02:00 GMT from the ship when its hull cracked.
He has now returned to his Royal Air Force base at Valley in Anglesey.
Flt Lt William Wales, as he is known in his job, qualified as a search-and-rescue pilot in September 2010 after a 19-month training programme.
Earlier this year he spoke of his work and admitted there were "hairy" moments for crews involved in rescues in the North Wales mountains.
He was involved in a mountain rescue in Snowdonia a week after his wedding in April, having returned to work before going on honeymoon.
By next summer, he hopes to have secured promotion and be able to take full charge of his helicopter and crew on rescue missions.
His Anglesey posting could last for three years, but he is expected to be posted to the Falklands next year shortly before the 30th anniversary of Argentina's defeat in the Falklands War.
The RAF says his posting there is purely routine but the Argentine government has called the move a "provocative" gesture.