Diver on trial over drowning of his bride

A fellow diver seems unaware of the body of Christina floating behind him, while an instructor (L) races to help her. Photos / Supplied

An American man has arrived in Australia to face trial for the murder of his bride of less than two weeks during a honeymoon dive on a Queensland shipwreck six years ago.

Now remarried, Gabriel "Gabe" Watson, 32, of Birmingham, Alabama, flew back voluntarily to avoid extradition in a bizarre case in which he is alleged to have drowned 26-year-old Christina while other divers circled the wreck of the steamer SS Yongala, which sank off Townsville in 1911.

Alabama police secretly filmed Watson using bolt cutters to remove flowers from her grave, secured after other tributes vanished mysteriously.

Evidence during the inquest indicated that Watson mistakenly believed his wife had increased her life insurance cover before their wedding, naming him as sole beneficiary.

Christina Watson was pulled to the surface by rescuers after Watson swam to a dive boat shouting that she had slipped from his grasp and sunk to the bottom of the sea on October 22, 2003.

Frantic efforts to revive her failed.

Watson, an experienced diver, told police Christina had started sinking beyond his reach as they descended to the Yongala after indicating she was in trouble and reaching for his hand but dislodging his mask.

After clearing his mask, he had been unable to reach Christina as she continued to sink.

"I don't know if she was still kicking or not but she was looking up, had both her arms out, you know, reached, stretched up almost looking at me ... so I kind of upended myself, you know, head first, and I remember going down," Watson told police.

The transcript of the interview said his wife had sunk faster than he could follow and he swam to seek help from other divers. When they failed to understand, he raced to the surface, shouting as he reached the boat, "Tina's gone down ... I need help."

Watson said he and his wife had not been told of the strength of the current around the Yongala. If they had known, they would not have dived.

Dive operators later testified that conditions were near perfect. Tests determined that Christina's equipment was not faulty, and an autopsy could not find any medical conditions that might have led to her death.

During the inquest, which Watson declined to attend, lawyer Steve Zillman said Watson lacked motive for the murder and the evidence did not support a criminal charge.

But Coroner David Glasgow said Watson might have killed his wife by cutting off her air and holding her down. "I am satisfied there is evidence of sufficient reliability ... that a properly instructed jury could make a finding of guilt against [Watson] on a charge of murder."

Watson has been remanded in custody until May 29.