This is a partial transcript of "The Big Story With John Gibson," April 23, 2007, that has been edited for clarity.

JOHN GIBSON, HOST: It is a big mystery, family members of three yachtsmen who set off more than a week ago for the trip of a lifetime, are now taking it upon themselves to search and try to find their missing loved ones. Investigators found a boat drifting at sea last week with the engine running, sails up, dinner on the table, but no crew anywhere. The officials have called off the search, relatives are pressing on. BIG STORY correspondent Douglas Kennedy has more on this desperate search. Douglas?

DOUGLAS KENNEDY, BIG STORY CORRESPONDENT: Yeah John, this boat was found 100 miles off the coast of Australia sailing by itself. Authorities say the crew had vanished and they have no idea why.

(BEGIN VIDEOTAPE)

KENNEDY (VOICE-OVER): Australians are calling it a ghost ship. A catamaran with raised sails and dinner on the table, sailing with no crew.

MIKE THOMAS, RESCUE PILOT: Wallets and telephones, sunglasses and things like that were still left on board the vessel and the sails were still set, so, it's a very unusual situation.

KENNEDY: Unusual is right, because there's still no sign of the 40 foot yacht's three member crew. Skipper Dez Vaugten and brothers Peter and James Tunstead were last heard from eight days ago, when they set sail from the northeastern town of Early Beach. Yesterday, Australian Coast Guard called off a massive search for the men.

ROY WALL, QUEENSLAND POLICE: Well, you know we really don't know for sure and it's probably dangerous to speculate. But obviously, they've become separated from the vessel, as simple as that.

KENNEDY: Australian authorities say they have found no evidence of foul play. Though some have speculated that pirates may have tried to board the boat. The men's families say they are not given up, calling the disappearance strange and unexplained.

WALL: The family are under enough stress as it is, so we still remain hopeful but (INAUDIBLE) have something.

KENNEDY: The families say they will conduct their own search of surrounding islands, in case they were swept overboard and swam to safety.

SHANE TUNSTEAD, SON OF MISSING SAILOR: We will be going out every day. We (INAUDIBLE) charter out of (INAUDIBLE) for tomorrow, after today, we'll just reassess and see what we can do tomorrow.

(END OF VIDEOTAPE)

KENNEDY: The families have now hired three different search boats and are combing the area where the catamaran was discovered. They say they will continue to search, John, until their loved ones have been found.

GIBSON: Were they in an actual pirate zone or was this kind of one of those deals where maybe one fell over and another one in after him and so forth?

KENNEDY: Authorities are saying they believe these guys got swept over. But they say there was only 20 mile an hour winds. So, you know that's not too big of a sea, especially if your boat is used to sailing you know way out there in the great barrier reefs, so. Nobody knows at this point.

GIBSON: Douglas Kennedy, Douglas thank you very much.

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