TORONTO - The legend lives on from the Chippewa on down, but the man who immortalized the sinking of the Edmund Fitzgerald has been moved to revise his iconic version of the story in light of some findings by a Canadian-produced documentary.

"They might have split up or they might have capsized. They may have broke deep and took water," Gordon Lightfoot speculates in his 1976 hit ballad chronicling the mysterious sinking of the Great Lakes freighter.

But in the first episode of a six-part television series debuting next week, a father-and-son diving team suggests a potential answer to the questions posed in Lightfoot's "The Wreck of the Edmund Fitzgerald."

In "Dive Detectives" - produced by Toronto-based Yap Films - Mike and Warren Fletcher try to debunk the long-standing theory that human error brought the ship down and killed all 29 crew members on board.

If the Dive Detectives are right, the ship was in fact sunk by a rogue wave - a massive wall of water that can reach up to 10 storeys high but was previously dismissed as a sailors' myth.

A report by the U.S. Coast Guard had previously blamed the crew for the disaster on Nov. 10, 1975, concluding they failed to fasten the hatches properly.

The conclusion never sat right with Mike Fletcher, senior member of the Dive Detectives.

The maritime community has always struggled with the notion that a crew would be careless when they were well aware of the fierce weather conditions coming on Lake Superior that night, he said.

"They knew there was a bad storm that was going to fall down on top of them. No sailor would go into a storm like that without double-checking the hatch fastenings and making doubly sure all over the ship that they were braced for bad weather. It just doesn't happen," Fletcher said in a telephone interview from his home near Port Dover, Ont.

Skepticism about the official record prompted Fletcher and his son, Warren, to investigate the case themselves, he said, adding they had access to recent high-quality footage that was not available to coast guard officials at the time.

Clear images of the bottom of the ship debunked one popular theory that the Edmund Fitzgerald ran aground and was damaged, he said.

The Dive Detectives felt the answer may lie in weather conditions and nautical patterns, which prompted them to assemble witness accounts, weather reports and other data about the day the ship sank.

Their findings ultimately led them to the Institute for Ocean Technology in St. John's, N.L., where they used wave-generating technology to simulate the actual conditions the Edmund Fitzgerald encountered in its final hours.

The simulation suggested the ship was particularly susceptible to the impact of large waves due to the 26,000 tonnes of iron ore it was carrying. Fletcher added the ship was known to be in less than pristine condition, noting it was due to go into drydock for repairs.

The simulation further suggested the presence of a rogue wave, once thought to only occur in turbulent oceans.

Such waves are usually caused when a group of waves travelling in different directions converge to create a giant wall of water.

When recreating the Nov. 10 storm conditions in the lab, Fletcher said the results were consistent with witness testimony and presented compelling evidence for the rogue wave theory.

"You don't ask it to send you a rogue wave, you put in the information to create the events of that day and rogue waves will suddenly appear," he said of the simulation technology.

Fletcher was not the only one convinced by the evidence.

Lightfoot saw the documentary when producers approached him asking permission to use his ballad in the soundtrack.

Lightfoot not only green-lighted the use of the song - which he has rarely done - but decided to revise some of its lyrics in all future live performances. The recorded version won't be changed.

Lightfoot has not revealed what lyrics he will substitute for the line "At seven p.m. a main hatchway caved in."

"I'm sincerely grateful to yap films and their program, The Dive Detectives, for not only making a terrific film about the loss of the Edmund Fitzgerald but particularly for putting together compelling evidence that the tragedy was not a result of crew error," Lightfoot said in a statement.

"This finally vindicates, and honours, not only all of the crew who lost their lives, but also the family members who survived them."

The revision to the most well-known song of the Edmund Fitzgerald's sinking came as a pleasant surprise to Fletcher, who said he never expected Lightfoot to revisit his own work as a result of the Dive Detectives.

"I'm a huge fan of Gordon Lightfoot and how he has sort of been the musical voice of Canadian history in his folk songs, and to think that an iconic song like that is influenced in a small way by something that I had a hand in, that's something I never imagined," he said.

"Edmund Fitzgerald" will air on March 31.