The man waited for treatment until the boat reached Great Barrier Island yesterday. He was treated by St John staff in Port Fitzroy before being flown to Auckland Hospital, just before 3pm, with moderate injuries.
Of the man's decision to wait until getting to shore the next afternoon, Deacon said he probably did not want to bother anyone.
"They are a fairly hardy bunch, fishermen," he said.
"He probably assessed he didn't need immediate care - but he certainly needed care."
Deacon said the man and his colleagues had done everything right by putting a compression bandage on the wound, which he described as "moderate", until the ship reached port.
Although the Auckland Westpac Rescue Helicopter could have winched the man from the ship if necessary, there were always risks associated with that, Deacon said.