Rescuers review search for missing US yacht

New Zealand rescuers were reviewing the search for the missing crew of a vintage US yacht on Friday, hours after a final message from the sailors caught in rough weather was released.

"THANKS STORM SAILS SHREDDED LAST NIGHT, NOW BARE POLES... WILL UPDATE COURSE INFO @ 6PM," the text message from the crew of the wooden yacht Nina, sent from a satellite phone on June 4 and released late Thursday, read.

The message was reportedly intended for a New Zealand-based meteorologist, but was never received.

The promised update never appeared and rescuers suspect the 85-year-old yacht sank in rough seas. They have expressed "grave fears" for the six Americans and one Briton who were aboard.

No sign of the yacht or its missing crew has been found after a search lasting more than a month.

The Rescue Coordination Centre New Zealand said it was examining all factors in the search, including the final message.

A spokeswoman said a military Orion search plane was not sent out to look for the seven missing sailors on Friday, but that did not mean the search was about to be abandoned.

"Not necessarily. All the information is being reviewed and assessed and there are no conclusions to be drawn at this stage," she told AFP.

The 21-metre (70-foot) Nina disappeared after setting off from New Zealand's North Island to cross the notorious Tasman Sea to Australia.

Searchers have covered almost 600,000 square nautical miles looking for the yacht.

Officials have not identified the crew but they were named in media reports as owner David Dyche, 58, his 60-year-old wife, Rosemary, their son David, 17, Kyle Jackson, 27, Evi Nemeth, 73, Danielle Wright, 18, and Briton Matthew Wootton.

In 1928, the Nina became the first US vessel to win the famous British Isles Fastnet race, according to an entry on the website by Rosemary Dyche.

She describes the schooner as the flagship of the New York Yacht Club after World War II before her husband bought it in 1988, detailing its restoration as "a labour of love".

In 2008, she says, she, her husband, and their son David first set off on the "dream" voyage around the world which ended in their disappearance last month.

The family wanted to "see the beauty of the world", she writes.