WELLINGTON, New Zealand – A New Zealand meteorologist took the last known calls from the seven people aboard an American schooner: “The weather’s turned nasty. How do we get away from it?”

The phone calls and texts ended June 4. More than three weeks later, searchers said Thursday they have grave concerns for the crew on the classic 85-year-old wooden vessel that went missing while sailing from New Zealand to Australia. Attempts to contact the crew by radio and an aerial search this week have proved fruitless.

Authorities say the skipper of the 70-foot vessel Nina is American David Dyche. They say there are two other American men and three American women aboard, between the ages of 17 and 73. Also aboard is a British man, age 35.

Messages posted online by friends indicate the boat originally left from Panama City, Fla.

Meteorologist Bob McDavitt said he took a satellite phone call from the boat on June 3. A woman named Evi asked how to get away from the weather. He said to call back in 30 minutes after he’d studied a forecast. She did.

“She was quite controlled in her voice, it sounded like everything was under control,” McDavitt said, but the call itself indicated she was concerned about the conditions.

McDavitt said he spoke only briefly to Evi, advising her to head south and to brace for a storm with strong winds and high seas. The next day he got a text, the last known communication from the boat: “ANY UPDATE 4 NINA? … EVI”

McDavitt said he advised the crew to stay put and ride out the storm another day. He continued sending messages the next few days but didn’t hear back. Friends of the crew got in touch with McDavitt soon after that, and then alerted authorities on June 14.

Kevin Banaghan, who is spearheading search efforts by Maritime New Zealand’s Rescue Coordination Centre, said rescuers weren’t worried at first because there had been no distress call from the boat and its emergency locator beacon had not been activated. He said rescuers on June 14 initiated a communications search, in which they tried contacting the boat over various radio frequencies as well as contacting other vessels in the area to see if they’d spotted the Nina.

This week, he said, rescuers escalated their efforts. An air force plane on Tuesday searched the area where the boat went missing. A second search by the plane on Wednesday went as far as the Australian coast but again turned up nothing. Banaghan said searchers are considering their next options.

Authorities say the storm three weeks ago had winds gusting up to 68 mph and waves of up to 26 feet.

Banaghan said the Nina is a “lovely old craft” that won races when it was new and had been maintained in excellent condition. He said it had a new engine installed in recent months.

He said there are several possible scenarios, including the boat losing communications, drifting off course, or the crew taking to lifeboats. He said there’s also a possibility the boat suffered a catastrophic failure and sank before anybody had time to react.

Susan Payne, harbormaster of the St. Andrews Marina near Panama City, Fla., said David Dyche and his wife, Rosemary, were very experienced sailors.

“We all have our fingers crossed for them here,” she said.