Close to 250 riders will contest the week-long event, which included yesterday's schools tournament.

The national championships get under way today.

"Kiama is the perfect setting for a contest of this magnitude" IBA Australasia general manager Terry McKenna said.

"This is a wave-rich area of the NSW coastline and it's well suited to handle the large number of competitors and their families.

"This is the culmination of twelve months of gruelling eliminations across Australia and New Zealand.

"Ten amateur divisions spanning from the grommets (under 13) to the grand masters (over 45) will hit the water at the infamous Kiama wedge, a punchy left hander that, on its day, produces world class waves that are highly conducive to high-performance bodyboarding.

"The last three days of the carnival will also see some of the world's best riders exchange blows in a heavyweight hit-out of the professionals in the Rebel Pro, a three-star event offering 1000 points to the winner and $10,000 cash."

Queenslander Mitch Rawlins holds a narrow lead for the national crown over NSW pair Charlie Holt and Jones Russell and fellow Queenslander Jake Stone.

Werri Beach riders Emma Cobb and Lilly Pollard are keen to make the most of local knowledge.

"There's nothing like competing at home," Pollard said.

"Sleeping in your own bed is a rarity for most world tour competitors so I'm really pumped to surf the wedge."