Here's another version, from Irish Come-All-Ye's: A Repository of Ancient Irish Songs and Ballads, compiled and arranged by Manus O'Conor (New York: L. Lipkind, 1901), page 15:


THE LAKES OF COLD FINN.

It was early one morning young William had rose,
Straightway to his comrades' bed-chamber he goes,
Saying: Comrades, royal comrades, let nobody know,
For it's a fine morning and a-bathing we'll go.

So they walked right along till they came to Long Lane,
And the first that they met was the keeper of the game;
He advised them for sorrow to turn back again,
For their doom was to die on a watery main.

So young William stepped off and swam the lake 'round,
He swam 'round the island, but not the right ground,
Saying: Comrades, royal comrades, don't you venture in,
For there's depth in false water, in the lakes of Cold Finn.

'Twas next morning, next morning, when his sister had arose,
She straightway to her mother's bed-chamber she did go,
Saying: Mother, dear mother, I had a sad dream,
That young William was floating on a watery stream.

It was early one morning when his mother went there,
She had rings on every finger and was tearing her hair,
Crying: Murder! oh, murder! was there nobody by
That would venture their life for my fine darling boy?

So it was early one morning when his uncle went there,
He rode 'round the island like one in despair,
Saying: Where was he drowned, or did he fall in?
For there's depth in false water, in the lakes of Cold Finn.