The punches flew fast and hard into his abdomen.
When they finally stopped, Mr Yeo Eu Loone (above) caught his breath and looked up - only to see a shotgun pointing at his head. The trigger was pulled twice but the shots flew past his ear and into the sea.
They were a reminder to the 38-year-old cargo officer - and 20 of his shipmates - that their lives belonged to the dozen African outlaws who had boarded the Hai Soon 6 oil tanker.
Mr Yeo was the sole Singaporean on board and had never had a gun fired at him before his ordeal off the coast of Western Africa less than three months ago.
After nine days of captivity, countless beatings, and eight weeks at sea as the Hai Soon 6 returned to Singapore, Mr Yeo finally made it home on Sept 25.
Speaking to The Sunday Times in his family's five-room Bedok flat, Mr Yeo still bears the scars on his knees and arms.
Dressed in a T-shirt and shorts, his voice solemn, he said he had nearly lost hope of making it home alive, and "would give up anything to not have gone through all that s***".
Mr Yeo still does not know how he managed to survive, but remembers the day the pirates took his ship, which had been on a supply route to refuel other ships off the coast of Western Africa.
On the night of July 25, he was in his cabin as the Singapore-owned tanker was filling up a larger ship when he heard a commotion coming from outside.
At first, he thought it was a scuffle between his fellow sailors, but when he went to investigate, he saw two burly African pirates wielding AK-47s and long knives, herding the other sailors up on deck.
One caught sight of Mr Yeo and grabbed him - then smashed his head with a knife handle.
It was the first of many beatings to come.
The sailors knew there was little hope of fighting off the pirates, who boarded from a speedboat.
The Hai Soon 6 had no weapons or armed security personnel on board to guard the $2 million worth of oil the tanker was carrying - the target of the invaders.
The pirates cast off the tanker from the bigger ship it was fuelling and disabled most of Hai Soon 6's communications systems. The bigger ship did not stick around and sailed off as soon as the pirates took over the Hai Soon 6.
However, Mr Yeo believes its crew alerted maritime authorities about the hijack.