Muriwai surf lifeguard Ash Matuschka is co-leading five other lifeguards on a 40-day round New Zealand voyage by liferaft - but it's his mum Linda who is getting the jitters.

"Ash is calm as, but I can't say the same for me," said Linda Matuschka yesterday morning, pacing the Auckland Viaduct as the men set off on their adventure.

"For the next 40 days when he's in the water, my thoughts will be with Ash, especially January 26, his birthday, when my baby turns 25."

The lifesavers hope to make history by travelling around New Zealand waters in two small inflatable boats, which have been modified to handle surf and open water.

Their adventure is also part of Surf Life Saving's 100-year celebration.

Mr Matuschka is promising his mother a "big, big hug" on his return, which is expected to be around mid-February.

He says the challenge for the team will be huge.

"Any lifeguard knows when you're up against the elements, you're completely at nature's mercy," said Mr Matuschka.

"We're as prepared as we possibly can be, but we also know to expect the unexpected."

He said while there was less concern over safety, the greater worry was over endurance and whether their bodies would hold up.

"It's a small boat, and we'll be confined to it for long periods of time ... a few rough days, being thrown about, and who knows?"

Mr Matuschka said the team had been preparing for this mission for about 18 months, and had given it everything.

"It's been all we have been thinking about, talking about, and it's still quite hard to believe that the day has come for us to set sail."

The voyage will be broken into 32 legs, and the group will call in at some popular locations as well as some remote beaches.

The most difficult and longest part of the journey will come at the end of this month when the lifeguards have to cross Foveaux Strait in the most isolated and treacherous part of the journey.

The president of Life Saving New Zealand, former Waitakere mayor Bob Harvey, said the organisation was enormously proud of what the men were hoping to achieve.

"This is a very daunting thing, very difficult and something that cannot be underestimated," Mr Harvey said.

"We are enormously proud of what they are doing, they are great adventurers and these men are great ambassadors for Surf Life Saving."

If successful, it will be the first time that a full circumnavigation of New Zealand, which includes Stewart Island, has been made in a craft less than 4 metres in length.

Mr Harvey said the challenge captured the essence and spirit of surf lifeguards.

But onlooker Robyn Smith said the attempt was admirable but she was worried it could encourage copycat voyages.

"At the peak of the summer drowning season, we will be without six lifeguards and that's a worry," she said.