Tenby's all-weather lifeboat was launched yesterday after a report from the tall ship Stavros S Niarchos, that a person had fallen and injured their head in rough seas.
The volunteer crew made their way to the ship through a three-metre swell and 35 knots wind.
A Coastguard Rescue helicopter from St Athan also assisted.
As the lifeboat reached the casualty vessel, the helicopter was also arriving overhead and began lowering the winchman to the deck to assess the casualty.
The job was made harder by the ship’s masts pitching from side to side in the swell but the winchman made it safely to the deck.
It was decided the safest course of action was to transfer the casualty in the lee of Caldey Island where there was much more shelter from the elements.
Once in the shelter of Caldey, the lifeboat managed to get alongside the Stavros and take the casualty aboard.
The casualty was then taken back to Tenby to be checked over at the lifeboat station by paramedics before being released.