In a video taken last month, a shark was spotted swimming around Weymouth Harbour on the Dorset coast.
But harbour locals needn't worry about getting a bigger boat just yet.
The man who took the video, who is a nature enthusiast, identified the creature as a starry smooth-hound shark.
A smooth-hound, usually found in offshore coastal waters, can grow up to five feet in length but represent little danger to humans.
Earlier this month, up to 50 sharks were spotted circling in a small pool of tidal waters at an RSPB reserve near Selsey, in West Sussex.
The sharks were a fearsome sight to passers-by who could see their distinctive fins sticking up through the water. The sharks were the same species as the one spotted in Dorset.
They're actually relatively common in the seas surrounding the UK, but are rarely seen - it's difficult to spot a single smooth-hound, never mind 50 at once.
Last month, two smooth-hounds were spotted at the reserve, but this latest massive gathering is the biggest yet.
Peter Hughes, an RSPB warden at the reserve told The Independent that the unusual sighting was "astonishing".
"There were just these huge fish everywhere in knee-deep water," he said. "We knew in time that Medmerry was going to be a great place for wildlife, but I don't think anyone expected this."
Unfortunately, shark-spotters might be disappointed if they want to see the shark gathering, as Peter said that they were unsure whether the remarkable spectacle would repeat itself.