Yachtie Alan Langdon and daughter Que reportedly spent three weeks at sea in their tiny catamaran with a broken rudder.

Langdon, 49, and his six-year-old daughter were originally believed to have set sail for the Bay of Islands when they left Kawhia Harbour on board their 6.1 metre catamaran on December 17.

Twenty-seven days later the pair were found alive and well in Ulladulla, New South Wales, Australia, on Wednesday afternoon.

Fairfax reports one of the catamaran's rudders broke four days into the 27 day journey and Langdon was left to steer with one rudder.

But the experienced yachtsman has played down any potential danger surrounding the voyage and has told local reporters in Ulladulla Que was 'happy”.

He says he'd not been able to make contact with Que's mother Ariane Wyler during their journey. She has since been notified.

Australian Border Force agents have made a port to port request for the Langdons to travel north to Port Kembla Harbour.

Following their disappearance back in December, an extensive search was conducted of sea and coastal areas between Wellington, Cape Reinga and the Bay of Islands.

The possibility Langdon had sailed to Australia had always been considered.

Mary Smith, who the pair lived with in Kawhia, told Fairfax she was overjoyed when she heard the news.

'That's all we have been praying for - for them to be safe and well. When he rings me and tells me and I can hear his voice, I will be happy.”

Waikato police Detective Sergeant Bill Crowe confirms Interpol had alerted Australian authorities of Langdon's possible arrival as part of the investigation into the missing pair.

- Stuff.co.nz