The message sent June 4 was never delivered to the friends of the six Americans and one Briton on board the Nina, a wooden schooner built 85 years ago, CNN reported Thursday.
"THANKS STORM SAILS SHREDDED LAST NIGHT, NOW BARE POLES. GOINING 4KT 310DEG WILL UPDATE COURSE INFO @ 6PM," the message read.
The transmission is critical because it provides teams an approximate location and the actual time of the last transmission, Nigel Clifford, Maritime New Zealand's general manager safety and response services, said. The data can be used to help rescue teams map search areas.
The ship went missing en route from New Zealand to Australia.
Authorities said they haven't been able to find the ship, even with the information.
"Today's radar search of more than 97,000 square nautical miles has been completed without any sighting of the vessel," the Rescue Coordination Center said Thursday.
The Nina may be a wooden schooner built in 1928, but it's tough, said Cherie Martinez, whose brother, David Dyche, is the Nina's owner and captain. He, his wife and their teenage son were sailing with four friends.
"Nina always comes back to port. She might get disabled, but she always comes back to port," Martinez said.