A sailor’s life is rough. You’re up against the weather, the sea, maybe even sea monsters — or so some sailors used to think. Since Ancient Greece, people have been describing sea monsters of various sorts, but according to one study, at least some of those monsters can be explained by something much more mundane: whale penises.

In one of the more famous sea sighting reports, Danish Lutheran missionary Hans Egede wrote that on 6 July 1734, he and those on his ship saw a terrible sight — a “most terrible creature”, resembling nothing they had seen before. The monster, Egede reported, was longer than their whole ship.

“It had a long pointed snout and it blew [spouted] like a whale [it] had broad big flippers and the body seemed to be grown [covered] with carapace and [it] was very wrinkled and uneven [rough] on its skin; it was otherwise created below like a serpent and where it went under the water again threw itself backward and raised thereafter the tail up from the water a whole ship’s length from the body.”

Egede’s account is notable because he was an educated man and had described several whale encounters previously, and as a man who had seen some things in his life, he wouldn’t be one to be easily impressed. So what did Egede and his mates actually see?

Three researchers took on the challenge of answering that question. The lead author was Charles Paxton, a man familiar with unusual studies. A few years ago, Paxton was awarded the Ig Nobel award for a study on how amorous ostriches attempt to court humans in Britain — yes, really. The Ig Nobel award is offered to research “that cannot, or should not, be reproduced” and that “first makes you laugh, then makes you think”.

Paxton’s whale study was carried out in 2005, and the researchers looked at all the plausible actions that could fit the description. A key part of the description is the “serpent-like” description.

“Although whales are found, and can survive, without flukes (for example grey whales ), serpent-like or eel-like bodies are not usually associated with the rapid thrust that would be required to rear the whole body high out of the water,” Paxton writes.

So it seems like the monster couldn’t have been a whale. But it could have been a whale… part.

“There is an alternative explanation for the serpent-like tail. Many of the large baleen whales have long, snake-like penises. If the animal did indeed fall on its back then its ventral surface would have been uppermost and, if the whale was aroused, the usually retracted penis would have been visible.”

This seems compelling enough, but it still leaves up the matter of size for debate. Whale penises are indeed impressive, but could they have been bigger than the entire boat? Researchers suspect the answer is ‘no’, but there could be an explanation: multiple whales.

“The penises of the North Atlantic right whale and (Pacific) grey whale can be at least 1.8 meters long and 1.7 meters long respectively and could be taken by a naïve witness for a tail. That the tail was seen at one point a ship’s length from the body suggests the presence of more than one male whale,” the study concludes.

To make the whale erection theory even more compelling, a separate incident from 1875 is even more likely to be a whale penis. Sailors aboard the merchant vessel Pauline reported seeing a “whitish pillar” amongst a pod of sperm whales “frantic with excitement” — a description that very well fits the whale penis theory.

Ultimately, we may never know what Egede saw, and probably not all sea serpent sightings are whale penises (though that would be an interesting study), but it seems to happen quite often, and it’s not uncommon for sea serpents to “appear” in the vicinity of whales, often even attached or “battling” a whale.

There’s even a theory that the Loch Ness monster is a whale penis, though there’s a big hole in that theory, in that Loch Ness is a lake and there are no whales in it. But otherwise, a lot of sea serpent sightings could actually be whale penises.

You can read the entire study here.