A tale from thirteenth-century Ireland: One day, when the people of Clonmacnoise were gathered in church, they spotted a ship sailing through the sky high above them. As they watched, the ship dropped its anchor, which scudded along the ground before catching on the church door.

Soon a man came swimming from the firmament, trying to free the anchor. But the people of Clonmacnoise took hold of him and wouldn’t let him leave. The bishop realized that the man was drowning in the air, as if he was being held underwater, and ordered his congregation to let him go. Up swam the mysterious sailor, away into the air.

In “Aerial Ships and Underwater Monasteries: The Evolution of a Monastic Marvel,” Celtic history scholar John Carey traces this tale back to its first unfurling. Like any good story, its details have been embroidered over many retellings. Carey identifies the legend’s first appearance in the historical record as just the barest skeleton of what it would become: a number of annals from the early 700s document sightings of ships sailing through the air.

By the early eleventh century, a more elaborate version appears: in this telling, people are gathered at an assembly when a sailor on one of the sky-ships spears a fish and swims down through the air to recover it. After another two hundred years pass, we find the full-fledged version recounted above, which comes from a Norse collection of “Irish marvels.”

These stories were passed along as wonders, but the idea that there was a sea arching above the sky was fairly conventional; after all, in Genesis, God “divided the waters which were under the firmament from the waters which were above the firmament.” The nature of these supracelestial waters were a point of debate for medieval scholars, with some arguing that they were frozen solid in a dome of ice and some insisting that they were merely a metaphor. Still others (like the twelfth-century encyclopedist Gervase of Tilbury) firmly held the position that an ocean over the sky was plain, literal fact.

To this end, Gervase recounts a story that suggests a rather mysterious relationship between the waters of Earth and the waters of the sky. In this story, a sailor from Bristol finds himself sailing in the most remote parts of the ocean. While on deck, he accidentally drops a knife over the side of his ship. It plunges through the water—and then falls through the open skylight of his house to embed itself, point down, in the kitchen table where his wife and children are eating breakfast. In this account, at least, the waters above and those that ran along the Earth’s surface were connected, and if you sailed far enough, you could find yourself floating above your own house.

Gervase’s explanation for the sailors in the first tale might be fairly simple: they came from our world and somehow managed to chart a course that sent them soaring over a little Irish monastery. Yet the fact that the sailor almost drowned while struggling with the good people of Clonmacnoise suggests that something even stranger was going on. As curator Michael McCaughan writes:

Essentially the central theme of the “airship” mirabilia is that, not only is an inversion of the natural order of things possible, but that the natural order of things can be perceived from complementary perspectives and that simultaneously the marvellous is both in the world and out of the world.

This vertiginous shifting of perspective, in which the marvelous and the natural are overlaid translucently on another, is illustrated beautifully in yet another tidbit of Irish folklore. As McCaughan recounts the story, St. Barra (Finbar) of Cork is sailing the oceans when he meets another holy man, St. Scoithin (Scuithin), walking over the waves.

“How is it that you are walking on the sea?” said Barra. “It is not the sea at all, but a flowery blossomy field,” said Scoithin, and he took up in his hand a crimson flower and threw it from him to Barra in the ship. And Scoithin said, “How is it that a ship is floating on the field?” At those words, Barra stretched his hand down into the sea and took a salmon out of it, and threw it to Scoithin.

Each saint’s perspective is perfectly logical and consistent within itself; the marvelous exists only in their meeting.

It makes you wonder what the tale of the airships would sound like from the sailor’s perspective. The air was like water to him, and the people were as threatening as you might expect malicious water-spirits to be, trying to hold him down in the depths as he began to drown. Did the grass look like seaweed to him? Did their church appear as a strange growth of coral?

In fact, as Carey notes, the Irish tradition provides another tale that reads almost as a perfect inversion of the airship lore. In this story, a group of monks is sailing to Rome, accompanied by a young blind man. Caught in a storm, they drop their ship’s anchor. When they try to weigh anchor after the storm passes, they find it’s gotten caught on something. The blind lad is sent into the sea to free it. He soon finds himself in an underwater monastery, where the anchor has snagged on the oratory building.

The lad stays with the monks for a year and learns the rule of their order. Meanwhile, his companions give him up as drowned and return home. A year later, they find themselves sailing at the same spot; again, a storm tosses them, and they drop anchor. Much to their surprise, the lost youth clambers back aboard the ship, bringing a bell from the underwater monastery as well as the order the sea-monks had taught him. The ship-monks subsequently adopt the order brought to them from the sea.

Putting the two stories together is like the meeting of St. Barra and St. Scoithin: an inversion of marvelous and mundane, mundane and marvelous, that leaves behind only a deep ambiguity about what is real.

Editor’s Note: This article was amended to note that the sailor who allegedly dropped his knife from the deck of his ship was from Bristol, not Ireland.

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