Search and Rescue co-ordinator Senior Sergeant Brian Benn said the boys, aged 16 and 17, began their journey about 4.30pm at Outram Glen, intending to meet a friend at Riverside.
When they failed to show up at the meeting point, the alarm was raised.
A Dunedin Search and Rescue team kayaked down the river and walked along the banks trying to find them.
As the river search continued, the teens were found safe at home about 8pm, Snr Sgt Benn said.
"They've gone halfway to their destination, come across a local resident on the side of the river who told them they still had quite a way to go, so they decided to take their boat and walk home, without contacting their friend.
"It was a happy ending, but it was something we could have done without."
Snr Sgt Benn was loath to chastise the boys, because he did not want to put people off calling the police for help when in similar situations, but he felt they could have been better organised.
"It was an unsuitable boat for that sort of water.
"They didn't have life jackets or wetsuits on, and they left too late in the day - they didn't allow enough daylight to reach their destination.
"So, they made quite a few departures from best practice procedure. It was foolish."
Snr Sgt Benn encouraged people to get out and enjoy the outdoors, but to do it "smartly".
"Be well prepared and you'll enjoy it a lot more."
