A 22-year-old Zimbabwean man studying in Port Elizabeth was swept out to sea in rip currents on Sunday afternoon, NSRI spokesperson Chris Lambinon said.
When the man disappeared under the water at the beach, which Lambinon described as "barely accessible", a massive rescue operation was activated.
Sardinia Bay Surf Lifeguards, who had been on duty at the swimming beach 100m away, started the search for him and a sea rescue craft was towed to Sardinia Bay, and pulled over the sand dunes to launch at the scene.
The Eastern Cape health department's medical helicopter Aeromed 3, Coastal Water Rescue rescue swimmers, NSRI Port Elizabeth and sea rescue swimmers along with the police all went out to look for him, said Lambinon.
His body was spotted in the surfline, 500m to the west, but the rough sea and rocks made it difficult for the rescue swimmers and the rescue craft to reach him.
The search had to be suspended at last light and a police dive unit will continue with a search and recovery operation on Monday morning.
His parents were visiting him from Zimbabwe at the time and are being helped by the police's trauma counsellors.