An air search for a schooner missing off the North Island for more than three weeks is likely to be extended as far south as Waitara in Taranaki.
Six Americans and one Briton were on board the Nina when it left Opua in the Bay of Islands for Newcastle in Australia on 29 May. It was last heard from on 4 June and grave fears are held for the crew's safety.
The historic American 21-metre-long (70ft) wooden vessel is equipped with satellite phone, a spot device allowing regular tracking signals to be sent manually and an emergency beacon, which has not been activated.
A search plane covered the area from 90 Mile Beach, past Cape Reinga to Northcape, and across to the Three Kings Islands on Friday.
Search and Rescue mission coordinator Neville Blakemore told Radio New Zealand's Checkpoint programme on Friday that conditions were perfect for searching, but there was no sign of the 85-year-old schooner or the missing crew.
The centre says it has not given up hope of finding survivors. A team will decide overnight where to continue the air search on Saturday, but it may be extended to the south. Mr Blakemore said land search teams, helicopters or the Coastguard will be called in if anything is seen from the air.
On board are Evi Nemeth, a noted American mathematician and data analyst. She writes textbooks and has held a variety of academic posts, including Colorado and California, before beginning an ocean voyage in her retirement. With her is an American couple, their teenaged son and two other Americans, as well as a British man.
AAP reports New Zealand meteorologist Bob McDavitt took the last known calls from the 85-year-old wooden boat before contact was lost, with Ms Nemeth asking him: "The weather's turned nasty, how do we get away from it?"
Mr McDavitt advised the vessel to head south and and brace for strong winds and high seas.
He received a text message the next day asking for an update, but received no reply to messages over the next few days.
