"If you do actually get caught, which is a dreadful situation, you need to immediately start yelling so that people around you can realise that's happened, and so they can try and keep an eye on you."
People should also try to "swim" down the avalanche, which was difficult, but the best anyone could do was try to stay near the surface.
"As soon as it comes to a stop or its starts to slow right down, you need to try and create an air pocket around your face so you'll have some room to breathe," he said.
But once an avalanche comes to a stop it sets like concrete and you cannot move.
"At that point, if you're buried in one, it's just sit there and be as calm as you can and start hoping that your friends have got the skills to come and get you."
The two New Plymouth men, once they had called for help, then had the Taranaki Alpine Cliff Rescue come to their aid.
"They were right up by the top of the crater entrance and the whole face just let go from in front of them. They were right at the very start of the avalanche and it carried them all the way back down," Mike Johns, who was one of the first on the scene, said.
One of the men suffered a suspected broken leg, and the other was thought to have dislocated his elbow and possibly broken some ribs.
"They were pretty happy to see us," Mr Johns said.
Taranaki Community Rescue Helicopter pilot Sam Richmond said he could see the path the avalanche had followed as he hovered above the mountain.
"It's a bit like the footage you see off TV; it went a good 400 metres down the mountain, in between a couple of ridges.
"The valley itself was fairly narrow - about 40 metres - which probably would have concentrated the force of the avalanche. Because of the size of the valley it wouldn't have been easy to escape."
Mr Richmond said the two men could count themselves lucky.
"I would think anyone who gets caught in an avalanche is probably lucky to get out alive. Certainly, if you get buried then you can't breathe, and if you can't dig yourself out then you're in trouble. If you smack a rock with the wrong part of your body then that would hurt.
"It looked like they were pretty well prepared - they had all the gear, including a survival blanket, which is what we noticed first, glinting in the sun, so we were able to determine their position pretty quickly."
Rescue co-ordinator Sergeant Andrew Ross said avalanches had not been expected at this time of year as there was not that much snow on the mountain.
The men may have triggered it by standing on loose snow, but this could not be confirmed.
Taranaki Alpine Cliff Rescue member Jeremy Beckers said it was not a part of mountain one would want to fall down.
"We've certainly picked up a few bodies at the bottom of that slope over the years."
