The Water Is Wide (also called O Waly, Waly) is thought to be an English or Scottish folk song and the stronger evidence points very firmly to it being Scottish.
Then there is the popular set of lyrics to this song that begin

The water is wide, I cannot cross o'er
Neither have I the wings to fly.
Give me a boat, that will carry two,
And both shall row, my true love and I.

These, according to a couple of very learned musical associates of mine (one teaches at the Birmingham Conservatoire), may well be Irish in origin... oops! :-D