A shark attack on a snorkeler off the British coast is being termed the most serious attack reported in the last 175 years.

A woman was on a snorkelling trip off the coast of Cornwall in southwestern England when a shark came out of nowhere and "bit her leg." The woman, however, is in stable condition and has no regrets about going on the trip.

The scary incident took place on Thursday during a snorkelling trip organised by a local tour firm. The trip was planned so tourists could take a close look at blue sharks. However, it is still unclear which kind of shark attacked the woman.

It is being termed the first shark attack of its kind in British waters since 1874, per a report in CNN. The woman, whose identity has not been revealed, was rescued by Her Majesty's Coastguard.

"HM Coastguard sent Penzance Coastguard Rescue Team to meet a snorkeler who suffered a suspected shark bite," a statement from the Maritime Coastguard Agency said.

Blue Shark Snorkel Trips, the agency that organised the tour, said that these "occurrences are extremely rare and can be easily misunderstood."

"As we know, these things can happen when we choose to interact with wild animals in their own environment. The last thing we want is to let speculation drive the media into a world of bad press for the sharks, under no fault of their own," they added.

The woman also warned people against misunderstanding the "majestic creatures." In a statement released through the firm, the woman said:"...it was amazing to see such majestic creatures in the wild and I don't for a second want this freak event to tarnish the reputation of an already persecuted species."

The presence of a shark in British waters is something that does not happen often. It is, in fact, a very rare occurrence. The country has not reported any shark bites in 175 years, per UK charitable organisation The Shark Trust.

Underwater Photographer of the Year 2016
A blue shark captured in Penzance, Cornwall, UK, 10 August 2015 Will Clark/ UPY 2016