The man has now been discharged, hospital staff said.
A diver died this month off the Northland coast after being struck by a boat propeller.
Bruce Porter was diving with Western Underwater Dive Club from Auckland on the Pacific Hideaway boat when he was struck by the propeller. He died of his injuries after being pulled back into the boat.
A rahui was put in place for the Landing Bay Pinnacle, where the incident occurred, and was lifted a few days later.
Dive! Tutukaka manager Kate Malcolm said divers would not be visiting the Landing Bay Pinnacle out of respect for his family for some time.
"It's not a site we would be visiting," she said.
This is only the second time a rahui has been placed on The Poor Knights Islands. In March, 2000, diver Astrid Malcolm died from an air embolism while diving at the Northern Archway at Tawhiti Rahi Island.
Ngatiwai put in place a rahui for the entire island for three days.
Usually a rahui is in place to stop people taking seafood from the site. However, because the Poor Knights Islands is a marine reserve it is to show respect after the death of a person.
Maritime New Zealand were supporting the police who were investigating the death.
A spokesman from Maritime New Zealand said it could be weeks before the investigation was complete.
