Rescue officials are becoming increasingly concerned for an inexperienced solo sailor who is overdue and possibly sailing into heavy weather off the East Cape.
The 20-year-old was spotted aboard the 6.7-metre Luna at Anaura Bay on Monday, when the sailor waved to an aircraft sent to look for him .
The Rescue Co-ordination Centre says the man was sailing from Napier to Auckland and had promised to call a friend every day.
He made a call on Friday night but has not been heard from since.
Weather in the area is deteriorating, with 30 knot winds, rain and low cloud expected later on Thursday.
"Our concern is this appears to be an inexperienced sailor heading into weather dangerous for a small boat and no one has heard from him," said search and rescue mission co-ordinator Mike Roberts.
Vessels in the area are being asked to look for the yacht and a Defence Force helicopter from Ohakea has also joined the search.
It is believed the yacht had a VHF radio and the skipper had a cellphone but there was no record of a distress beacon on board.