William and Kate to take to the water in New Zealand

Britain's Prince William (right) and his wife Catherine, the Duchess of Cambridge, chat with guests during a state reception at Government House in Wellington. - AFP

AUCKLAND, April 11, 2014 (AFP) - Prince William and wife Catherine plan to test their sea legs Friday racing America's Cup yachts against one another on Auckland Harbour on day five of their New Zealand tour.

The royal couple will visit Team New Zealand's harbourside headquarters then, weather permitting, take to the water on rival America's Cup boats.

William told Prime Minister John Key at a function on Thursday night that both he and Kate were looking to gain bragging rights over each other in their nautical showdown.

"It will be a competition... a bit of healthy competition," he said.

Team NZ chief operating officer Kevin Shoebridge said the race was expected to take about two hours.

"They're free to pretty much do what they want, we haven't been given any restrictions," he told 3News.

"We're hoping to start the boats and then we'll hand the wheel over to them, give them a little bit of tuition and let them do it themselves... I think everyone will have a good time."

The royals will be hoping for a better performance than Team NZ produced when they lost the America's Cup final to US rivals Oracle in San Francisco last year.

The team were up 8-1, needing just one more race to claim victory, before collapsing spectacularly and losing 9-8 in what has been described as the greatest choke in sporting history.

The royals will also meet New Zealand air force personnel Friday at a base just outside Auckland and go on a brief walkabout in New Zealand's largest city, as well as cross the harbour in an amphibious vessel.

Lobby group Republic New Zealand said that while the royals are on the water it plans to send a plane above Auckland trailing a banner reading "Time for a New Zealand head of state".

"Having the UK supply us with a head of state no longer works for New Zealand, we need our own head of state," the group said in a statement.

Baby Prince George is travelling with his parents on the three-week tour of New Zealand and Australia but remains at their Wellington base with recently appointed Spanish nanny Maria Teresa Turrion Borrallo. - AFP