They were rescued by the volunteer fire brigade, who travelled down from Ahipara as the nearest helicopter was located in Auckland.
The brigade used an inflatable rescue boat (IRB) after being unable to get assistance from Coastguard.
Ahipara Volunteer Fire Brigade chief fire officer David Ross said they received the call at about 8pm after a 7m aluminium boat overturned in the harbour entrance.
He said one member of the crew had swum ashore to raise the alarm, while local boats assisted in pulling people out of the water before the rescue IRBs could bring them ashore.
The family group, aged from their early 20s to 60s, spent around an hour and a half in the water before being rescued.
"Everybody was happy and smiling and a bit worse for wear," Ross said.
"They seemed quite happy to be rescued, but two of them had been cut up - one person quite badly because he had swum to shore. The other one had cut up feet from the oysters on the rocks.
"They were all taken home and reunited with their family."
He said, while they did have lifejackets aboard the boat, no one was wearing one.
The shift manager for Auckland-Northland fire emergency said staff were cheering when they got the news of the safe rescue.
Police and the Auckland Westpac Rescue Helicopter were also involved in the rescue.
Rescue Helicopter chief crewman Mark Cannell said conditions were challenging due to low light, low cloud and heavy sea spray.
"Westpac 1 commenced a shoreline search, locating some items and then the upturned vessel including a couple of life jackets," he said.
"Crew continued searching and were advised all five occupants had been uplifted by two RHIBs - surf lifesaving and private inflatable boat.
"Westpac 1 landed and intensive care paramedic Chris Deacon helped assess all patients, four males and one female. All patients were in a minor condition.
"Transportation to hospital by Westpac 1 wasn't required."
