Tauranga Coastguard was called to rescue a man from Tauranga Harbour late Friday night.
A police media spokeswoman said police received reports of men fighting in a Tauranga street at 11.45pm on Friday.
Following the fight one of the men swam into the harbour, the spokeswoman said.
"He was holding onto a boat and started to swim away," she said.
Tauranga Coastguard was called to assist and pulled the man from the water at 12.45pm.
"He refused to climb onboard [initially] but did a couple of minutes later," the spokeswoman said.
St John Ambulance was also called to the scene.
A 27-year-old man has been arrested and charged with assault and escaping from police.