A 63-year-old man from the UK died while scuba diving in Simon's Town in the Western Cape, the National Sea Rescue Institute (NSRI) said on Sunday.
NSRI Simon's Town station commander Darren Zimmerman said the medical response team were alerted to the emergency by a dive charter boat at 11am on Saturday.
Zimmerman said CPR was administered to the man who collapsed after surfacing from a scuba dive with his daughter.
It is suspected he had suffered a heart attack.
His family is being assisted by trauma counsellors from the police and City of Cape Town tourism officials.
The British high commission was also assisting the family who were holidaying in South Africa.
