The body of John Roberts, a crew member, was found 21 metres below the surface at 11am on Sunday by divers from the SA Navy, the city said in a statement.

A charter boat, The Maroshka, capsized near Duiker Island around 3pm on Saturday.

About 34 people were rescued and one of the men was declared dead on arrival at Hout Bay NSRI sea rescue station.

Initially the NSRI said that four people died and that 33 or 34 people were on board, but later revised the numbers.

The NSRI said it was initially believed that up to six people were missing and this number was later revised to four people still missing.

It was later confirmed that 38 people had been on the boat when it capsized.

The SA Maritime Safety Authority (SAMSA) has deployed a tug boat to recover the charter boat and begin an investigation into the cause of the accident.

When the NSRI arrived they found that some people had been rescued by two charter boats. At the time, four people were still missing, three women and one man.

Three were found inside the hull, using air pockets to breathe. They were all rescued by divers.

Two of the women are believed to be from the United Kingdom.

Of those rescued, 24 people were hospitalised for further medical treatment. Twelve people did not require to be hospitalised and were assessed and treated for hypothermia before they were released.

The man who died is believed to be from the United Kingdom.