Here's another variant resembling somewhat Christie's version, from Northumbrian Minstrelsy: A Collection of the Ballads, Melodies, and Small-Pipe Tunes of Northumbria; edited by John Collingwood Bruce, John Stokoe; 1882.
I Drew My Ship into the Harbour
I drew my ship into the harbour, I drew her up where my true love lay, I drew her close by up to the window, To listen what my dear girl did say.
"Who's there that raps so loud at my window That raps so loud and fain would be in?" "It is your true love that loves you dearly, So rise, dear girl, and let him in."
Then slowly, slowly, got she up, And slowly, slowly, came she down; But before she got the door unlocked Her true love had both come and gone.
"Come back, come back, my only true love, Come back, my ain one, and ease my pain; Your voice I knew not, your face I saw not, Oh John my heart will break in twain."
The ripest apple is soonest rotten, The hottest love is soonest cold; Seldom seen, is soon forgotten, True love is timid, so be not bold.
He's brisk and braw, lads, he's far awa' lads; He's far beyond yon raging main, Where fishers dancing and dark eyes glancing, Have made him quite forget his ain.