A team of 'cautiously optimistic' scientists are hunting for great white sharks off the Irish and UK coasts.

US non-profit research organisation Ocearch believe great whites do indeed roam the depths around Ireland and Britain.

They're aiming to create history by finding one off the southwest coast of Ireland.

"It would be the shark heard around the world," Chris Fischer, founder of Ocearch, told Sky News.

"It would be the greatest thing we have ever achieved on the water. It would be the greatest gift we could give to any region of the world for their future, because that one shark would show people in this area and other research institutions where they can then potentially work on them and get more of the work going."

For decades, the possibility of great whites in British or Irish seas has remained a mystery.

Unconfirmed sightings are few and far between and hoaxes have been known. 

There has never been a confirmed great white shark sighting in British or Irish waters - however - scientists believe the conditions are perfect.

Shark expert Dr Nick Payne, assistant professor at Trinity College Dublin's School of Natural Sciences, is the lead Irish scientist on the new Ocearch expedition.

Recommended reading:

Great white sharks believed to be roaming the Spanish coast

40ft sharks may arrive in the UK as early as next month

Mysterious sharks lurking in the depths of British waters

Rarely Seen Species Filmed On Newly Discovered 'Underwater Mountain'

"I think given the conditions we have in Britain and Ireland in terms of the water temperatures and the kind of food that's available, the kind of habitats that exist on the seabed here, I think there's a really good chance - these are exactly the kind of conditions, this is like a Goldilocks environment for these animals," he said.

He continued: "It's not too hot, it's not too cold, the food here is right, both here in Ireland and throughout different parts of the UK.

"This whole region is potentially a really comfortable place for them. It's just a matter of trying to find out if they're here."