Zarifeh was a physical education teacher at Christchurch Boys' High School.
His father Paul passed away on November 23.
He died at home, surrounded by family after a battle with pancreatic cancer.
The 27-year-old was the nephew of Christchurch Crown Solicitor Mark Zarifeh.
He is survived by his mother, sister and brother.
The Herald has contacted the Zarifeh family for comment.
Police are investigating the specific circumstaces of Zarifeh's death.
They confirmed that he was one of four people on the raft.
The occupants of the raft were on a private trip - it was not operated by any other person or company.
CBHS headmaster Nic Hill released a statement on the school website this morning after learning of Zarifeh's death.
He said the young teacher was also a master at one of the school's boarding houses.
"Sam was with other School staff members when the accident took place," he said.
"Sam is loved by the Boys' High and Adam's House communities.
"Our heart's go out to Sam's family, his friends and the wider Christchurch Boys' High Community.
"We are doing everything we can to support those who have been affected including making sure we can get those who were with Sam at the time of the accident back to their families safely."
Hill said he would update the school website and Facebook page with information as it came to hand.
He invited "anyone who needs support" to gather today at Adams House, where Zarifeh was house master, to meet with other members of the school community.
"Sam's death will be difficult for us all," he said.
"I know that we will support each other.
"Please do look after yourselves and seek the support of the Boys' High Community."