In a summer filled with one of the most oppressive heat waves in memory, it’s not like beach-goers need something else to worry about, but now there are unconfirmed reports of a shark patrolling the waters off the coast of Massachusetts’ Duxbury Beach, according to Boston’s WCVB News.

There have reportedly been at least two sightings of a shark haunting the waters just off the coast, although there has yet to be any concrete documentation of the beast’s’ existence. Whether it’s true or not, visitors to the beach have taken to etching a warning into the sands, drawing in super-size letters, “BEWARE SHARK.” The status of the beach is currently “swim at your own risk.” 

The Duxbury harbormaster’s office is looking into the sightings, issuing a warning for beach-goers to remain alert, and to report any further sightings. According to experts, a number of tagged white sharks have been roaming closer to shore lately, but whether this is an anomalous behavior remains to be seen. In the meantime, it’s probably a good idea to stay close to shore.