Floating altars were a stock element of the Lives of the Celtic saints. St Brynach, in his 12th C. Life* (Translation), sails across the sea on a rock, as does the follower Nimannauc in the 12th C. Life of St Padarn* (Translation). St Patrick* (Translation) is asked for a lift on his boat by a leper: strangely there's no room, but he gives the leper his stone altar to float on, and it swims around the boat as they travel. In the same 12th C. Life, St Patrick's altar also floats behind him along the road when he tries to leave it in Connactia to heal people*. Saint David (Translation* of 11th C. Life by Rhygyfarch or "Ricemarch") is given an wonder-making altar in Rome, in which the body of Jesus had lain, and it is miraculously transported to Wales for him. This too seems to have a taboo against looking at it, as it is covered in skins and unseen since its priest died.

Conversely, some stones were too fixed: St Machaldus' bones were said to rest in a stone sarcophagus from which a spring leapt, but which no one could dig around to clear (See Patrick's 12th C. Life*).

Such events are sometimes used to make a religious point through metaphor ("[Brynach] mounted the rock, because he was founded on a firm rock, that is, Christ")1. The cheesiest example of this is in Jocelyn's Life of St.Patrick* (Translation), in a story about him moving a giant stone which has 12 rock-related metaphors in it2. However, this is relatively rare. The degree to which the specific theme of floating altars relied on older traditions is unclear - their popularity may just be because altars were the heaviest single items Christian communities could repectfully consider (monoliths being pagan), and floating was the last thing they would usually do.

More on the body in the boat.