La Belle
The wooden planks found bear similarities to La Belle (pictured), another one of La Salle's ships.Richard Gross

An explorer claims to have found the long lost French ship Le Griffon at the bottom of Lake Michigan.

Steve Libert, from the Great Lakes Exploration Group, said he is 99.9% certain the team has discovered the vessel that sank in the 17th century in the lake after searching for it for decades.

Speaking to the Associated Press, he said the crew found debris just 120ft from the area of Lake Michigan where a wooden slab believed to be from René-Robert Cavelier, Sieur de La Salle's sunken ship was discovered last year.

Le Griffon is thought to be one of the first European ships to sail the Great Lakes. Captained by La Salle, it disappeared with six crew members on its maiden voyage in 1969, just after La Salle had disembarked.

Libert believes the slab is the bowsprit of Le Griffon, however other experts have said it could be a fishing net stake.

Libert said: "This is definitely the Griffin (sic) — I'm 99.9 percent sure it is. This is the real deal."

La Belle
Wooden parts of La Belle.Richard Gross

The team found an area about the size of a football field covered in wooden planks that could form part of a ship, including the bow, hull and sections of the mast. While they have not found any concrete evidence that the find is Le Griffon, nails, wedges and fasteners appear to be similar to those found on La Salle's ship.

Images of the debris have been sent to underwater archaeologists from France, who said the find was "encouraging" but that more evidence is needed to confirm the ship's identity.

Explaining why he is sure the ship is Le Griffon, Libert told IBTimes UK he has a lifetime of research to back him up. He said the bow sprit discovered last year is centuries old, and that finding a wreck field so close to it -- containing wood and iron fasteners from the 17th century -- strongly suggests it is Le Griffon.

The Griffin
Sonar scan of what is believed to be Le Griffon.Steve Libert

"They were compared to that of another of LaSalle's ship's fasteners that sank in 1686 off Texas 'La Belle'," he added, noting that they bore remarkable resemblance.

Libert said he first became interested in Le Griffon when he was 14 during a history lesson about European explorers in the US.

"[My teacher] spoke of LaSalle and his ship, Le Griffon. He described the figure head as part lion and eagle. He spoke of the territory that La Salle claimed for King Louis XIV. Much of that land we know today as The Louisiana Purchase.

"My interest was piqued and suddenly [he] came up from behind me, put his right hand on my left shoulder and said, 'who knows, maybe one day someone in this room will find La Salle's ship Le Griffon'."

Libert said they are awaiting permits for further exploration of the site.

French archaeologists will head the project as the ship belongs to France:

"We expect the archaeological excavation to begin in the spring of 2015 although non-invasive probing will take place in September 2014."

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