The tanker Brunswick rammed by giant squid between Hawaii and Samoa

The 1930s. A ship named Brunswick was crossing the Pacific Ocean between Hawaii and Samoa. The exact year is lost. The best record gives a span, 1930 to 1933, and one later retelling settles on 1930. Her master was Arne Grønningsæter. He is the only witness ever named. The crew appear in later versions of the story, but never by name.

It began alongside the ship. A giant squid was swimming next to the Brunswick, matching her pace. Grønningsæter put its speed at 20 to 25 knots. He based that figure on three observations.

Then the squid turned. It came straight in toward the ship and struck the hull about 150 feet from the stern, some 12 to 15 feet below the surface. It did not hold. It went on, in Grønningsæter's words, "skidd[ing] along until it ended up in the propeller, where it was ground to pieces."

Later retellings add their own colour. One says the squid "pulled alongside the ship, paced it, then suddenly turned and wrapped their tentacles to the hull." Another describes how they "slid to the rear of the ship and were chopped up by the ship's propellers." By these accounts, it happened three times.

Grønningsæter did not publish his account until 1946. It appeared in the Norwegian journal Naturen, with a sketch he made himself. That was 13 to 16 years after the events. No report from the 1930s has surfaced.

Over the decades the story drifted. The Brunswick has been called a freighter, a Royal Norwegian Navy auxiliary tanker and a Norwegian tanker. Most sources give her 15,000 tons. One gives 8,890. A version credited to Bob Eggleton and Nigel Suckling makes the attackers 9m squid ramming a 150m hull. The earliest summary gives the animal no size at all.

There was no official inquiry. But one scientist took the captain seriously. Marine biologist Frederick A. Aldrich cited the Brunswick in the Bulletin of Marine Science in 1991, as evidence of how fast a giant squid can swim. Aldrich accepted the speed. Richard Ellis returned to the case in his 1998 book The Search for the Giant Squid.

The explanation most often offered is simple. The squid mistook the large grey hull for a whale, its prey or its enemy. It attacked. Its tentacles found nothing to grip on the smooth steel, and the hull carried it aft.

The doubts run deeper. The veracity of the account has been questioned. The speed alone invites scrutiny, since a sustained 20 to 25 knots is fast for Architeuthis. And no register entry for a Norwegian ship named Brunswick from the 1930s has yet been found.

Today the Brunswick sits in the lists of giant squid sightings, beside the schooner Pearl and the steamer Strathowen, the classic squid attack of 1874. Blogs, columns and podcasts still retell it. A ship. A squid. A propeller. And a captain's sketch, still waiting in the pages of an old Norwegian journal.