A great white shark called Lydia is set to become the first of her species ever seen to cross the Atlantic Ocean - and she's heading in the direction of Ireland.
The 14ft-long female, which has been fitted with a satellite tag, has completed a transatlantic crossing in the last 24 hours according to Massachusetts State senior marine fisheries biologist Dr Gregory Skomal.
He says no white sharks have ever been documented crossing from west to east or east to west.
“She has crossed the mid-Atlantic ridge and is now closer to you [Ireland] than to us, but it looks as if she is heading north,” said Dr Skomal.
Lydia is currently about 745 miles off the Irish coast, having passed the mid-Atlantic ridge - a rough boundary line between east and west.
To track her movements click here
The 2,000 lb shark was first tagged off the coast of Jacksonville, Florida, in March 2013 as part of the Ocearch scientific project.
She has since travelled 19,500 miles and is currently around 3,000 miles from her starting point, having spent some time meandering off America's East Coast.
Dr Skomal said he was "surprised" at the shark's behaviour, adding: "White sharks may well have been crossing the Atlantic forever, but this is the first time we're actually able to observe it."
There are plenty of shark species in British and Irish waters. In 2011 a fisherman caught a 300lb (21 stone) porbeagle shark off the coast of Donegal.
But the great white - the ultimate predator at the top of the marine food chain - has never been spotted here. The nearest official sighting was off La Rochelle in France.
Feared as man-eaters, they are only responsible for about 5-10 attacks a year, which are rarely fatal.
The Ocearch project aims to gather "previously unattainable" data on the movement, biology and health of sharks to protect their future while enhancing public safety and education.
Tagging a great white is no mean feat. The scientists use a custom-built 34,000kg (75,000lb) capacity hydraulic platform to tag sharks. Operated from their research vessel the M/V Ocearch, it allows them to safely lift mature sharks from the water.
Lydia's journey is impressive, but the sharks are known for their marathon migrations.
A great white nicknamed Nicole travelled from South Africa to Australia and back - a circuit of more than 20,000km (12,400 miles) - over a period of nine months between November 2003 and August 2004.
Leading Irish marine biologist Kevin Flannery believes the great white could be the first of many more of her kind to head towards Irish shores.
"(Lydia) could be here in 72 hours if it took a straight line but it probably won't go directly in a straight line. She is an eating and feeding machine hunting for food," he told the Sunday Independent.
The director of Dingle Oceanworld in Co Kerry believes the worldwide ban on hunting sharks is swelling their numbers and sending them hunting for food in the north Atlantic and towards the coast of Ireland.
"They are protected worldwide now and there are a greater number of them and more of them which can move further north. Possibly we will see more of them," he said.
"For science, it is absolutely brilliant to see a great white moving into the north Atlantic."
Ocearch is currently tracking around 70 sharks.
As for where Lydia might go next, Dr Skomal said: "We have no idea how far she will go, but Europe, the Med, and the coast of Africa are all feasible."