HMNZS Wellington sailed through Hurricane-strength winds and 16-metre swells yesterday, forcing it to alter its course and ultimately turn around after suffering some superficial damage.

Winds gusted to 90 knots (166kmh) as the offshore patrol vessel passed through the eye of the storm, in the vicinity of the Snares Islands, with gale-force northwesterly winds buffeting it for most of the day.

The ship was forced to change direction so it was driving into the storm, rather than across it.

The nose of the ship regularly drove through the waves, sending blankets of spray across the bridge windows as it pitched and rolled and dived through the storm, sending regular groans through the ship.

On board are Conservation Minister Nick Smith, Department of Conservation and Metservice staff, businessmen Gareth and Sam Morgan, and some media.

Lieutenant Commander Phil Rowe, the captain of the ship and a 28-year Navy veteran, described it as the worst sea he had sailed in. "It was hell on earth that one. It was quite scary," he said.

"You've got 80 people on board who are relying on me for their safety. When that ship was coming down in those troughs and shaking, that's the worst part for any ship.

"A couple of those yesterday I was quite concerned and I think if you spoke to anybody else [they would say the same]."

Other officers admitted to being scared for the first time in their careers.

The crew, many of them seasick, were sent back to bed as the conditions were too rough to work in.

Rowe made the decision to turn around and seek shelter at Stewart Island as another storm approached, to undertake repairs although the damage was largely superficial.

Ross Carroll, a Metservice volunteer who has lived on two of the sub-Antarctic islands and previously sailed through the same seas, said he had never seen conditions like it.

"It's quite interesting to see how scared the crew are," he joked during the storm yesterday.

"If I was in a smaller boat I'd be nervous.

"You can see photos, you can see film but . . . you don't know the sensation of it.

Asked how he was faring with many of the crew and passengers seasick he added: "I'm not great but I'm hanging in there."

Mike Lowe, a TVNZ cameraman who couldn't leave his small top-bunk due to sea sickness, joked: "It was like being in a floating coffin.

"Just alone with your thoughts which is not necessarily a good thing."

Lying in bed he said he would try to picture what was creating the noise.

"The rolling and crashing was quite frightening, I don't know about you but I was quite scared with it," he said.

Gareth Morgan said he had never seen seas that big.

"For me the dramatic thing about the sea was that the boat couldn't turn, it had to run with it," he said.

"I've never been in a seas quite that big so that was a new experience. But today you can walk out on the deck and take photos of albatross so we're back to normal, everybody's happy."

The itinerary for the two-week trip will be reassessed at Stewart Island.