A 16-year-old boy says he was pleased to see a police officer who swam more than 100m through rough conditions in the Otago Harbour to get to him after his yacht capsized.

When Thomas George found himself in the harbour on Saturday, police and his coastguard member father, Neil, raced to save him.

The actions of Constable Rhys Davidson in stripping down to his underwear and swimming through metre-high swells have been lauded by his commanding officer.

Inspector Jason Guthrie, of Dunedin, called Mr Davidson's actions "the kind of conduct that makes you proud to be a police officer".


Mr Davidson responded to a 9.30am call-out from members of the public concerned about Thomas' safety.

Thomas said after the capsize he initially panicked, but then calmed down and tried to put the centre board back into his yacht to try to get it back up "but it never happened".

"Then I actually just gave up and sat there. Altogether I was in the water about 40 to 45 minutes."

Thomas was sailing from Macandrew Bay to help at his father's sailing class at the Vauxhall Yacht Club when he capsized.

Mr Davidson said he asked his patrol partner to drop into the yacht club, where, although he did not know it, the boy's father was teaching his students about sailing.

When he got to the incident there were about six members of the public, and the upturned hull of the yacht between 100m and 200m out.

"I looked out there, and you could see there were whitecaps and the conditions were rough.

"You could see the shape of a person clinging to the hull.

"Without knowing the situation, I said to my partner 'I'm going out there, I'm swimming out there'."

A member of the public who had a wetsuit also offered to help.

Mr Davidson said waves were breaking over his head ashe swam out. He was not a regular swimmer, but was confident of his ability.

"I was taking in some water, but just get there - that's what it is."

It was not a frightening experience, as his goal was to get to Thomas.

"I'd happily say any police officer would do the same. I just happened to be the first police vehicle there."

He found Thomas safe, and "happy to see me. I apologised I didn't bring my notebook and pen with me."

Thomas was wearing a wetsuit and lifejacket and was an experienced sailor, but the sea had "chopped up" after he left.

By the time his father arrived in the inflatable boat, Thomas was starting to cramp up.

Mr Davidson said the water was cold but he was not getting close to hypothermia.

Mr George, a Yachting New Zealand instructor, said he had talked his Thai, American and German students through scenarios for evacuations the previous night.

"We got to put it into play. It's what they call a teachable moment."

At Vauxhall he was "rigging up and preparing for our sailing day" when he saw ambulances driving past the yacht club, and got on the radio.

"The initial information that I was receiving on the radio was there were three or four people in the water."

Mr Roberts said he stopped his lesson, took "the most nautical" student and "went and did our thing".

He said he had thanked Mr Davidson for his efforts. Thomas said: "It was just sort of nice to have someone out there making sure I was OK."