In 1918, a group of professional crayfish fishermen working out of Port Stevens on the coast of New South Wales, Australia, stopped fishing their regular grounds near Broughton Island for several days. These were experienced fishermen who worked those waters for a living, and taking multiple days off from paid work was an unusual and costly decision.

David George Stead, a naturalist who managed the state’s trawling industry at the time, happened to be on the Nelson’s Bay wharf while lobsters were being packed for the Sydney market. He asked the men whether a recent southeast storm had cost them many pots. According to Stead’s account, published in his 1963 book “Sharks and Rays of Australian Seas,” the fishermen did not discuss the storm. Instead, they spoke with visible excitement about what they described as one great big shark.

Stead later recorded that the fishermen described a shark of what he called almost unbelievable proportions, appearing repeatedly at their fishing grounds and lifting pot after pot straight up off the seafloor, crayfish and all. The men said the animal took the pots, mooring lines included, rather than simply damaging or scattering the equipment the way a storm surge or an ordinary large fish might.

The crayfish pots in question were about 3 feet 6 inches across and frequently held two to three dozen good-sized crayfish, each weighing several pounds. A trap of that size, fully loaded and anchored to the bottom, represents a substantial object.

Stead recorded a specific detail, writing that the fishermen described the water boiling over a large area as the animal swam past and that they had seen its head directly, describing it as at least as long as the roof of the wharf shed at Nelson’s Bay. He noted the men were familiar with whales, regularly seeing them pass offshore during their normal work, yet they insisted this was unmistakably a shark rather than any whale they recognized.

When pressed for a size estimate, individual men gave numbers ranging from the length of the wharf they were standing on, about 115 feet, up to one man’s insistence that it measured at least 300 feet. Stead openly acknowledged these figures were almost certainly exaggerated well past anything physically plausible for any known shark species.

Stead was not a casual bystander looking to sensationalize a story. He was a working naturalist and ichthyologist whose professional reputation depended on giving the government and fishing industry accurate assessments of the state’s waters. He later founded the Wildlife Preservation Society of Australia, reflecting a career built on careful observation rather than sensationalism.

According to his own account, Stead did not simply take the fishermen’s word at face value. He followed up directly, questioning many of the men closely alongside the local fisheries inspector, a man named Payton. Stead described the men as prosaic and rather stolid, not given to fish stories, and noted they already knew Stead had heard every exaggerated fish story imaginable over the years, making them unlikely to invent one purely for his benefit.

Stead reported that despite the wildly inflated individual size estimates, every man he and Payton questioned agreed independently on the basic gigantic scale of whatever they had encountered, and specifically on one detail Stead found significant: the animal’s distinctly ghostly whitish color. Inspector Payton agreed with Stead’s assessment that whatever these fishermen had seen, it must have been genuinely enormous to put grown, hardened professional men into visible fear.

The formal follow-up investigation conducted by a fisheries official rather than a journalist is why this specific 1918 account has continued generating discussion among marine biologists and historians more than a hundred years later.

The writer Zane Grey, known for Western novels but also a dedicated big game angler, spent considerable time fishing Australian and South Pacific waters during the 1920s and 1930s. He published an account of his fishing experiences in a 1937 book called “An American Angler in Australia,” built from magazine articles he had written for Field and Stream.

In his 1931 book “Tales of Tahitian Waters,” Grey described sighting an enormous shark while sailing near Rangiroa in French Polynesia around 1927 or 1928, describing an animal with a square head, huge pectoral fins, and a length considerably exceeding his own 35 to 40-foot fishing boat. Grey’s account differed from the Port Stevens description in one notable way, describing the animal’s body as green, yellow, and speckled with white spots, rather than the uniform ghostly white color the Port Stevens fishermen had independently agreed on.

Researcher Michael Roe, examining both the Port Stevens and a separate Great Barrier Reef sighting, has pointed out that the ghostly white coloration described in these reports does not match the known confirmed coloration of any living giant shark species. Basking sharks and whale sharks both typically display darker mottled or spotted patterns rather than a uniform pale white.

Researchers who have revisited the 1918 Port Stevens account in recent years have raised an alternative explanation: that the fishermen’s crayfish pots, and possibly a boat, had simply been damaged or destroyed by the same southeast storm Stead originally asked them about, and that the men invented or exaggerated a monster shark story to cover their financial losses. Skeptics have also pointed to the wildly inconsistent size estimates as a warning sign, arguing that such a wide range suggests panic, poor visibility, or genuine misperception played a larger role than an actual single consistently-sized animal.

Neither skeptical explanation has been definitively proven. No physical evidence from the 1918 incident survives.

Modern marine biology has confirmed real living shark species considerably larger than most people realize. Whale sharks, the largest fish species alive today, have been confirmed reaching lengths of up to roughly 61 feet, feeding primarily on plankton and small fish through filter feeding rather than attacking large prey or equipment directly. Basking sharks, the second largest living fish species, follow a similar filter feeding lifestyle, typically reaching lengths of around 26 to 33 feet.

Neither of these two confirmed giant shark species behaves anything like the aggressive, gear-stealing animal the Port Stevens fishermen described. Both are docile, slow-moving filter feeders posing essentially no threat to fishing equipment or people. Great white sharks are genuinely aggressive predators capable of investigating and damaging fishing gear and do grow to a confirmed maximum length of around 6 meters, but that falls far short of even the most conservative 115-foot estimate the Port Stevens fishermen gave.

That mismatch between the real confirmed biology of the world’s actual largest living sharks and the specific aggressive behavior described in 1918 leaves a genuine gap in any simple explanation.

Some retellings online have speculated the 1918 Port Stevens shark might represent a surviving population of megalodon, the enormous prehistoric shark whose fossil teeth turn up regularly across multiple continents. Paleontologists studying well-dated fossil sites in California and Baja California have placed megalodon’s extinction at roughly 3.6 million years ago based on the point where its distinctive fossil teeth stop appearing in the sediment record.

A 2023 study published in the Proceedings of the National Academy of Sciences added a biological reason behind that extinction timeline, finding through chemical isotope analysis that megalodon maintained an unusually warm body temperature relative to surrounding seawater, a trait requiring enormous constant amounts of food that likely became impossible to sustain once global oceans cooled sharply and the large whale species megalodon depended on either died out or migrated toward colder water.

No fossil evidence has ever been recovered anywhere near Port Stevens tying this particular 1918 account to that species one way or the other.

Considerably more recent Australian discoveries have turned up real, scientifically confirmed giants in these same general waters. In July 2026, researchers working through Curtin University in collaboration with the Schmidt Ocean Institute and the Western Australia Museum confirmed genetic evidence of a giant squid living in deep ocean canyons off the coast of Western Australia’s remote Ningaloo coast. Dr. Lisa Kirkendale, head of aquatic zoology at the Western Australia Museum, described the discovery as the first record of a giant squid detected off Western Australia’s coast using environmental DNA testing methods.

Giant squid rank among the largest invertebrates on the planet, growing between roughly 30 and 40 feet long and weighing up to 600 pounds, with eyes measuring up to 12 inches across. Despite deploying cameras and remotely operated vehicles down into the Cape Range and Cloates submarine canyons at depths exceeding 14,000 feet, the research team never captured direct visual footage of the animal itself. The genetic material recovered from water samples proved a real giant squid had been present in that exact stretch of ocean.

Australian waters have produced physical giant squid specimens before as well. A confirmed 500-pound giant squid washed up dead in a trawler’s nets off the country’s southeastern coast in waters more than 1,640 feet deep, an animal a fisheries research biologist at the time confirmed required ten men simply to lift onto a stretcher.

In 2020, researchers aboard the Schmidt Ocean Institute’s research vessel Falkor, using a remotely operated vehicle called SuBastian, documented an enormous siphonophore belonging to the genus Apolemia while exploring the Ningaloo Canyons, estimated at approximately 45 meters long when its full string-like structure was measured. That length would make it among the longest animals ever recorded anywhere on the planet.

A siphonophore is technically a colony made up of many smaller genetically identical individual organisms called zooids, each specializing in a different function like feeding, swimming, or reproduction. Researchers studying these colonies have noted that sightings like this suggest these massive soft-bodied colonies may be more common in the deep ocean than scientists previously expected.

Australia’s coastline borders an unusually large stretch of deep, largely unexplored ocean, including submarine canyons dropping to extreme depths just off otherwise popular coastal regions like Ningaloo and Port Stevens itself. That geography creates opportunities for large, deep-dwelling animals to occasionally surface into or near shallower waters where fishing boats and casual observers might encounter them.

Marine biologists and historians revisiting the 1918 Port Stevens account today generally land between full belief and complete dismissal. The witness testimony came from multiple independent experienced professional fishermen cross-examined directly by a credentialed naturalist working alongside an official fisheries inspector, a combination that carries real documented weight. At the same time, the size estimates given were wildly inconsistent and at their upper range physically implausible for any confirmed shark species.

No physical evidence, no recovered tooth, no photograph, and no confirmed carcass has ever surfaced connecting this specific 1918 incident to any particular species, leaving the case permanently short of the kind of proof that would let modern science settle it definitively.

What has changed considerably since 1918 is the sheer volume of confirmed evidence showing that genuinely enormous, previously undocumented animals really do live in exactly this kind of Australian coastal deep water. Evidence that did not exist for Stead or the fishermen he interviewed at the time.

In 1918, a group of experienced crayfish fishermen working out of Port Stevens stopped fishing their regular grounds near Broughton Island for several days after encountering what they described as an immense ghostly white shark, one large enough to lift entire anchored crayfish pots, mooring lines, and contents straight off the seafloor. Stead and Inspector Payton questioned the men directly, finding consistent agreement on the animal’s gigantic scale and pale coloring, even though individual size estimates ranged wildly from 115 to 300 feet.

Whether the 1918 Port Stevens fishermen genuinely encountered some enormous still-undocumented animal, badly exaggerated an encounter with a large but ordinary shark, or invented the entire story to cover storm-damaged gear remains a question nobody has settled with hard physical evidence. What modern Australian marine research keeps confirming is that the deep water sitting just off this same coastline is still fully capable of holding genuine scientifically significant surprises.