There are two different tunes/song named "The Bay of Biscay" in the Database (and also at The Contemplator) but this is clearly a third.

I'm listening to a longer version as done by Norma Waterson on Broken Ground. It's clearly a 'William-is-gone-to sea' - revenant lover - Child #248 of "The Grey Cock"/"Night Visiting Song" (no birds, no waking father) and very nice, too.

Carthy only gives his two sources, Mary O'Connor of Wexford and Deirdre MacLennan of Inversess.

Mary mourns for her William who went to sea and didn't come home. He knocks her up one night but his "cherry cheeks were as white as snow" and he admits to being a ghost. At dawn he says he must go. But he's sad. The first & last verse has him gone on a tender off across the Bay of Biscay, Oh and gone seven years. She's sad too.

Any knowledge of this?