"Ariel's Song" is a verse passage in Scene ii of Act I of William Shakespeare's The Tempest. It consists of two stanzas to be delivered by the spirit Ariel, in the hearing of Ferdinand. In performance it is sometimes sung and sometimes spoken. There is an extant musical setting of the second stanza by Shakespeare's contemporary Robert Johnson, which may have been used in the original production.
"Full Fathom Five" is the second stanza of "Ariel's song", better known than the first, and often presented alone. It implicitly addresses Ferdinand, who with his father has just gone through a shipwreck in which the father supposedly drowned.
It is the origin of the identically worded catchphrase, which means "at a depth of five fathoms [of water]", and thus, in most evocations, drowned and lost as the father is. Prior to modern diving technology, an object lost in five fathoms of water would be considered irretrievable.
Full fathom five thy father lies;
Of his bones are coral made;
Those are pearls that were his eyes;
Nothing of him that doth fade,
But doth suffer a sea-change
Into something rich and strange.
Sea-nymphs hourly ring his knell:
Ding-dong.
Hark! now I hear them — Ding-dong, bell.
This stanza also provided the source of the contemporary English usage of "". Modern usage of the phrase is seldom specific to the sea or drowning, but generally refers to any change that was unanticipated and seems "beyond recognition" in degree.
The lines of Ariel's Song do not indicate whether the "sea change" was caused by the application of Prospero's magical powers, or whether it was solely the result of a natural metamorphosis of the body as it rested in the environment of the deep sea.