Their unsettling discovery gained traction after it was shared online, sparking debate among viewers about what the shape was, or if it was simply an illusion created by the waves.
The local rescue unit, SES Chelsea, had reported a shark sighting in the same area on the same day.
In a Facebook post, they stated: “We posted about a shark sighting, just off the beach, between Bonbeach and Chelsea. Well later, we received a message from a family, who follow our page, who were at Carrum Beach earlier in the morning.”
The post continued: “It was their little one’s first visit to the beach, and the gentleman’s partner grabbed a couple of snaps to record the day.
“Later, when they got home and looked at the pictures, they noticed something in the shallow water, just behind them. Was this our shark?”
Social media users quickly weighed in with their opinions. Some believed the image truly showed a shark fin, while others dismissed it as a coincidence.
One user commented: “Couldn’t be a very big one, given the size of the dog and the depth of the water.”
Another expressed skepticism, writing: “Looks a bit shallow for a shark that would have a fin that size, judging by where the dog and guy to the left are standing. Wouldn’t the other guy behind them have noticed?”
A third person added: “I agree that it can’t be discounted – but it’s highly unlikely that a shark cruising in the shallows would not be seen and those in the photo not aware.”
This eerie beach sighting follows another recent shark encounter in Australia.
Just days before, a massive great white shark, reportedly the size of a boat, was spotted near Aldinga Beach, south of Adelaide, MailOnline reports.
The 13-foot predator was seen patrolling the coastline, prompting officials to issue a public alert.
Fishermen captured footage of the shark circling their vessel less than half a mile from shore, using their boat for size comparison to estimate the shark’s length.
Beachgoers were warned to stay out of the water as authorities monitored the situation.
The incident served as a stark reminder of the potential dangers lurking beneath the surface of Australia’s coastal waters.