Researches tagged the right Great White shark when they began tracking a 14-foot female off the coast of Jacksonville in 2013. Since then, "Lydia" has traveled more than 20,000 miles and across the Atlantic -- two unprecedented feats in the brief history of Great White tagging, National Geographic reported.

"We're really just starting out in the world of white sharks," Greg Skomal, the scientist at Massachusetts Marine Fisheries who tagged Lydia, told Nat Geo.

Swimming from some point of the western side of the Atlantic and into its eastern side past a point of underwater volcanoes known as the Mid-Atlantic ridge qualifies as a crossing, according to Nat Geo. That's about where Lydia is right now as she continues east towards Britain's coast.

Lydia's motivation for such intense travel likely relates to food, which also spurs the great distances swum by Great Whites of the Pacific Ocean, according to Nat Geo. Along the way, she stopped at locations rich in feeding opportunities.

Probably, Lydia's swim isn't that unusual -- scientists have long suspected it could be done -- but it's important to note for several reasons. For one, it could mean that Great White populations near Europe may not actually be a different species (a rule that could also apply for Mako sharks). Second, a better understanding of an animal's range aids in conservation efforts.

That Lydia was a female may also be significant. Few large ones have been tagged, however, the previous record holder for longest swim was also a female (just over 12,000 miles, or 8,000 miles less than Lydia).

"That seems to be the typical pattern for females," said Heidi Dewar, a biologist with the U.S. National Marine Fisheries Service in La Jolla, California. "They'll give birth, then they "go off and forage, and travel pretty wide distances for two years or so, and then they come back."

"I think it's really exciting that they're starting to get these kinds of tags out there so we can get this information," she added. "The large females are a really important part of the population, and until you know what's going on, it's hard to develop conservation strategies to protect them."