The cloak of mist is the most enduring motif in the Manannán tradition. When enemies approached the Island, Manannán mac Lir would wrap it in fog, hiding it from sight. The Traditionary Ballad, composed between 1504 and 1522, records it plainly: “when he would see ships sailing, he would cover it round with a fog.” The Supposed True Chronicle elaborates that Manannán “was a paynim” who “kept, by necromancy, the Land of Man under mists,” and that if he feared an enemy, “he would of one man cause to seem an hundred, and that by art magic.”

The Manx Gaelic word for the cloak is cloagey druiaght — the invisible cloak. Charles Roeder recorded it in 1904. It is a Manx word, not borrowed from the Irish, for a specifically Manx tradition. The Irish equivalent, feth fíada, appears in several of the major Irish mythological texts. In the Wasting Sickness of Cúchulainn, Manannán arrives “in a magic mist,” takes back his wife Fand, and shakes his cloak between her and Cúchulainn so they can never meet again. Cúchulainn takes a draught of forgetfulness. The cloak does not just hide islands. It separates lovers and erases memory.

Morrison places Manannán at Peel Castle, where he once caused a single man standing guard on the battlements to appear as a thousand, sending the enemy fleet away in terror. In another version, he made boats from sedges, creating the illusion of a great fleet in Peel Bay. A god who fought with fog and grass — easy to dismiss, but hard to forget. The cloak survives in everyday Manx speech. When the sea mist settles along the coastline, someone will say it: Manannán’s cloak. A piece of mythology so embedded in daily life that people repeat it without thinking about what they are saying, or who they are remembering.