Working in pairs with local authorities, they tried to get people out of their houses to safety as quickly as possible.
He described the "devastation and shock" of seeing familiar streets submerged.
"Pulling up people's driveways in a boat is quite moving," he said.
"There was water flowing through garages, over the top of cars, a good 50 to 60 per cent of properties we went to the water was up to the windows."
People's belongings were floating in the chest-deep water and beloved pets have been lost in the deluge, Crowley said.
"We just have to be thankful we got the people out when we did."
One man Crowley rescued flagged the boat down from his waterlogged house when he woke after working a night shift to find himself in knee-deep water.
"The water was lapping at his bed, so he was an example of one of the lucky ones who managed to get out."
Today Crowley will be helping move logs and debris in Whakatane as the town enters its second day in a state of emergency.
If needed, he will return to Edgecumbe in his jet boat this afternoon.