The royal couple launched the space with William giving a speech after Prime Minister Jon Key mentioned how much New Zealand loves the couple and their baby boy.
CLICK ON KATE AND WILLIAM IMAGES FOR GALLERY:
Host Jon Bridges had warned those in attendence that rules for Avantidrome included no selfies, which William has done with admirers on past outings, plus no mention of changing the flag, on a day where so many New Zealand dwellers flew the Union for the British guests.
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At the venue people also waved ferns and provided the loudest cheers of the day for the couple before William fired the starting gun. While tunes by Coldplay and Rihanna were said to have been played, they were shown around by gold medal-winner Sarah Ulmer. Son George was also gifted with a bicycle.
The parents are on their tour of New Zealand
As well as that they could be seen watching a BMX display and meeting a selection of Olympic athletes. The venue had shared a snap on Twitter of the red carpet rolled out for the grand opening from early that morning.
The two are in the region as part of the royal tour in New Zealand, which began April 7 with husband the Duke of Cambridge plus their son Prince George and a hefty entourage. They are due to head to Australia for the second leg of the trip next week after nine days in NZ.
Kate and William had previously been in Cambridge in order to pay their respects at the war memorial. Apparently the small Waikato town got its name from a cousin of Queen Victoria; the Duke of Cambridge, George William Frederick Charles.
Cambridge was named after the Duke of Cambridge to honour his years as a Commander-in Chief of the British Army.
The best opportunity for the public to see them was when they drove around at 12:45pm, then walked to the Town Hall to see the mayor. The day before they had raced each other on former Team NZ yachts at Auckland Harbour and Duchess Catherine was triumphant.