The three were winched to safety more than an hour later by the Otago Regional Rescue Helicopter crew, having floated with the life ring which was not recovered.
Senior Constable Kellas, of Portobello, welcomed the national recognition for Coastguard Dunedin.
He said the life ring was such a simple thing but it "paid dividends".
It was installed using a community board grant, following the death of a man fishing from Cape Saunders in 2010.
Since the May 27 incident, a replacement life ring had been installed at the cape and another two were donated to Coastguard Dunedin, which planned to put one at Puddingstone Rock and keep the other as a back-up.
In early August Mr Ferguson and Micah were awarded Dunedin Marine Search and Rescue and Water Safety New Zealand certificates for their efforts at Cape Saunders.