Rescue crews searching for a classic American schooner carrying seven people believe the boat sank between New Zealand and Australia, although they haven't given up hope of finding survivors.

A Chattanooga woman who's the fraternal twin of the captain of the Nina thinks the 1929 racing schooner may be limping along slowly toward Australia -- undetected by searchers scouring the vast Tasman Sea that separates the two countries.

"We haven't given up hope," said Cherie Martinez, whose brother, David Dyche, 58, is a lifelong sailor. "We think the boat was damaged, and because they [had battery failure] they can't tell us that."

A third day of aerial searches Friday turned up no sign of the 85-year-old wooden sailboat or its crew. The boat left New Zealand on May 29 bound for Australia. The last known contact with the crew was on June 4.

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