Willie Calder, skipper of Argosy, responded to a Mayday call from Silver Fern, which had run aground in Curio Bay.
"We dropped everything and came straight away," Mr Calder said.
Steaming at 11 knots, it took Argosy almost four hours to reach the stricken vessel.
"We were very lucky. It worked out perfectly. We got there right on high tide," Mr Calder said.
Using a nylon rope about half a kilometre long, Argosy "tugged" at Silver Fern for about an hour before prising it loose.
"The suction was keeping him stuck to the sand. We watched the waves and when a good roll went past, we gave him a good pull," he said.
Silver Fern was refloated at 11.20am.
Constable Richard Lindsay, of Wyndham, said the boat had moored in the bay overnight, and skipper Owen Beaton had woken up to find it stuck on sand.
"We don't know if the anchor rope snapped, or what [happened]."
Maritime New Zealand senior media adviser Sophie Hazelhurst said the Rescue Co-ordination Centre received a Mayday call at 5.47am.
The crews of two rescue helicopters dispatched by the centre found Mr Beaton and deck hand Luke Ryan uninjured, but stranded in their 12.1m trawler.
"The pilots advised they were high and dry, and were safe," Ms Hazelhurst said.
Maritime NZ is now waiting for an accident report to be filed by the company which owns the vessel.
The Otago Daily Times could not contact Mr Beaton for comment yesterday.
