The Dimboola sea serpent in the Great Australian Bight

The Dimboola was a Melbourne Steamship Co. steamer of about 2,104 tons. In May 1913 she was bound from Adelaide to Fremantle, crossing the open water of the Great Australian Bight. Her master was Captain William Millar.

Wednesday, 14 May 1913. 11.15 a.m. The position was "lat. 35.30 S., lon. 133.40 E." Passengers shouted. The third officer, on watch, looked "over the starboard quarter." He saw a school of porpoises and a whale "fleeing from a tremendously large sinuous monster."

Millar and the Marconi operator turned their glasses on it. The man at the wheel and several saloon passengers watched too. "It alternately reared its head and ducked it under the waves." At times it arched its body. It was "of the colour of a brown seal," with a head between the size of a whale and a porpoise and a tail "of the exaggerated fish variety." It "rose several feet out of the water," as if chasing the fish. Then "the fish altered their point and made north."

It stayed in view long enough for Millar and the wireless operator to sketch it. Passengers drew it too. Their sketches reportedly agreed closely.

The ship reached Fremantle about 20 May and the news went out by telegraph. "The sea serpent has at last made its appearance in Australian waters," ran the first report. It gave a length of "at least 50ft." Millar's signed letter to the Sunday Times in Perth placed the creature "about half a mile from the ship." An artist's redrawing of his sketch showed a serrated fin on the neck and back.

The crew took "a good deal of chaff." Millar received a mock certificate from a "Fish Liars Association." "Like all Scotsmen I appreciate a joke even if it is against me," he told the Herald in Melbourne. He added that its head was visible "10ft. or 15ft. above the water," with "an appendage hanging from its chin like a goatee beard." Then he set the record straight. "I did not say that it was a sea serpent or that it was at least 50ft. long."

H. C. Dannevig, the Commonwealth Director of Fisheries, accepted that the witnesses saw something real. But "my belief is that they saw a fight between a large whale and a number of killers." Millar answered that those on board were better placed to judge than an expert hundreds of miles away. The naturalist David G. Stead suggested a giant squid.

In June, officers of the steamer Alcinous at Port Pirie saw what looked like a huge fish about 100 yards long. It was a school of seals swimming in lines. The ship's surgeon, Dr Montgomery, suggested the Dimboola witnesses had made the same mistake.

Malcolm Smith counted 144 references in Australian papers over the following three weeks. New Zealand papers reprinted the story, but it never spread further. Revisiting the case in 2018, Smith judged it probably a misperception, since size and distance are hard to read at sea. Yet seals, he noted, do not explain the fleeing porpoises and whale, the rising head or the fish-like tail. In 2022 Robert France linked the beard and crest of a 1913 sighting from the Sunday Times, apparently this one, to fishing gear tangled on an animal. No photograph was ever taken. Only the drawings remain.