Constable John Fredericksen of the Rotorua police Search and Rescue squad said Kawarau Jet Rotorua offered to take two police officers on to the lake to bring the man back.
Fredericksen said the man, who was from Hawke's Bay, was able to walk about 1km into the lake, given it was shallow, then swam the rest of the way.
Police alerted the Coastguard, who were on the other side of the lake attending to a towing callout, and they met the police onboard the Kawarau Jet boat.
Police got the man in the Coastguard boat and he was placed under arrest.
He was originally charged with resisting police and disorderly behaviour but after an assessment with a mental health nurse the charges were dropped and replaced with a formal written warning.
"It was a fantastic effort by Kawarau Jet and the Coastguard. They did everything by the book and it ended up a great result, which could have been different," Fredericksen said.