The Rescue Coordination Centre (RCCNZ) is deciding its next move, after a search by a maritime surveillance aircraft on Sunday found no trace of a missing yacht's lifeboat.
Six Americans and a Briton were on board the 21 metre vintage schooner Nina which left Opua in the Bay of Islands for Newcastle in Australia on 29 May and was last heard from on 4 June.
The centre's spokesperson Sarah Brazil says staff on Sunday used a P3 Orion aircraft to search slowly, and at a close range, for any signs of a life-raft or debris.
She says it focussed on a 4830 square nautical mile area, north-east of Northland, but did not find anything of interest.
Ms Brazil says the centre will now re-assess all its information.
On Saturday, a helicopter searched the coastline from Port Waikato to New Plymouth but found no sign of the vessel or its crew.
The RCCNZ said the two sea-based searches it had co-ordinated covered a combined area of 500,000 square nautical miles, and two shoreline searches had been carried out.