A text message asking for advice about sailing on in bad weather was the last communication from missing schooner, Nina.
The message was sent to a meteorologist on June 4, six days into its voyage from Opua in the Bay of Islands for Newcastle, Australia, and about 370 nautical miles west-northwest of Cape Reinga.
The 21-metre Nina, built in 1928 and described as a beautiful, race-winning vessel, set out on May 29.
Maritime New Zealand has grave concerns for the seven crew members, saying the journey was expected to take 12 days.
Six Americans - three men aged 17, 28, and 58, three women aged 18, 60, and 73 - and one 35-year-old British man were on board.
Their experience ranged from a professional sailor and the captain, to another man on the boat who had no boating experience, said Rescue Coordination Centre New Zealand's (RCCNZ) Kevin Banaghan.
RCCNZ was contacted by concerned family and friends and started a "communications search" on June 14.
No sign of the vessel was reported by any other vessel in the area.
Nina was equipped with a satellite phone, a spot beacon which allowed regular tracking signals to be sent manually, and an emergency beacon. The beacon had not been activated.
Banaghan said a Royal New Zealand Air Force Orion had also been sent out and completed two extensive searches.
On June 25 a search area of 160,000 square nautical miles was covered, to the immediate north-north east of New Zealand, based on estimates of where Nina would be if it was disabled and drifting.
Yesterday a search was completed of 324,000 square nautical miles between northern New Zealand and the Australian coast, based on the vessel suffering damage but continuing to make progress towards Australia. No sign of the vessel was found.
"If it did come to grief, it would have been catastrophic and quite quick I imagine," he said.
"The sea conditions at the time were 8 meters and winds gushing to 65 knots so it wouldn't have been pleasant."
The emergency beacon, located in the cabin, was likely to be a hydrostatic release beacon, he said. This meant it would either need to be manually released, or it would go off when it got wet.
"In the event it sinks very quickly, it may have been trapped in the vessel, and we won't get a signal if it goes under water any depth at all," Banaghan said.
He said the estimate of a 12-day trip was "very ambitious" given the weather conditions, especially given they had been asked to wait out the storm. The Australian Maritime Authority did not expect them to arrive before June 25.
But the crew could still be on their journey with no problems, or the vessel could have suffered damage and the crew then taken to a life raft, Banaghan said.
The New Zealand rescue centre is liaising with the Australian Maritime Safety Authority and will continue to review search options.