Wiremu Wiremu, white handlebar moustache wuffling and bristling, is overseeing the setting up of his waka boot camp.

"Hey, that table's missing a leg! Put a bread roll on it and it'll bloody collapse!"

A boy scurries to rectify the fault as round the modest Waitangi public campground, teams of young men erect tents, assemble trestle tables, lift boxes and lay sawdust.

Although Mr Wiremu, a Waitangi kaumatua, bellows a lot, a gruff affection is just discernable beneath the surface. He was a regimental sergeant major for decades and, well, some habits never quite wear off.

He commands the Waitangi Treaty Ground's huge war canoe, Ngatoki Matawhaorua, and is revered by the Maori youth who find direction and sometimes salvation in his waka training.

For three decades he has led the koha-funded camp, where word-of-mouth attracts old hands and raw beginners to drill (mostly on land) and learn haka and karakia.

Over the best part of a week, about 500 young, mostly Northland, men are prepared for their roles in the waka fleet that spectacularly frames formal Waitangi Day celebrations at the Treaty Grounds. Among them is Mohi Kara, a softly spoken 32-year-old from Kaeo whose Black Power past is revealed by the fist tattooed on his bicep.

Taking a break from tightening guy ropes, Mr Kara says he first came to the camp as an 8-year-old. At 16, he started prospecting for the gang and camp fell by the wayside.

After being released from a four-year jail sentence in 1998, "I just wanted something positive to teach my three kids and my nephews".

So he and Mr Wiremu crossed paths again. Mr Kara has been back at the camp for five years, where he is now a leader with a crew of 18.

"It's the waka life that changed my outlook," he says.

By that he means the discipline of teamwork, which brings not only fitness but a beautiful, spiritual feeling.

"We are all bonding together as one, although we are in different tribes and different waka."

Mr Kara is conscious of the responsibility of being a leader, of how younger kids look up to them; they also looked up to him during his 12 years as a patched gang member.

Mr Wiremu says many of the young men at the camp are disadvantaged - "we cry with them sometimes" - and have no sense of identity; of having a place in this world.

The waka often provides that.

"A lot of these boys live for it. Going out in the waka is a thrill."

Murphy-James Munroe, 13, of Moerewa, doesn't yet know that excitement, but he can show the drills he has learned.

"It's hard and [it makes you] sore," he says, holding his arms rigidly at shoulder height to demonstrate his least-favourite exercise.

"But it's fun and you meet a lot of people."

Even so, campers are weeded out if attitude or skills are deficient.

Mr Wiremu expects that the waka camp will outlive him.

"A lot of these boys have been since they were very little, when they were bailers on the waka. They're now leaders," he says.

"And indeed if I turn my toes up tomorrow morning, they'll be in good hands. These guys have really weathered the storm.

"I don't think I'm that gentle with them. Original Maori discipline is harder than military discipline, but it gets results."

He half-smiles, wuffles that distinctive moustache and seems to be about to say something, but then his attention leaps elsewhere. "Hey!" he shouts, moving off.

"Pick that up! Hammer and lawnmower do not agree!'