Click here to get to the lyrics in the Digital Tradition database for "Of all the harbours east and west." Entering "biscay" in the search box in the upper-right corner of this page will bring up more than one song, but may also bring up more information.
Here's the introduction to "The Bonny Bay of Biscay-O" in Traditional American Folk Songs from the Anne & Frank Warner Collection

We have been able to find no information in print about this song. English friends have told us that this is one of the folk songs blandly thrust upon small English school children, with no information about its origin or usage. There is a version of the "Gypsy Laddie" (Child No. 200) in which the chorus says, "Some sang high and some sang low, and some sang 'The Bonny Bay of Biscay-O.'" The song has not been found elsewhere in America, although a song of the same name appears (words only) - with very different words - on page 515 of American Folk Poetry, edited by Duncan Emrich. That song may be heard on Library of Congress field recording AFS, 4464B as recorded by Alan Lomax from the singing of Mrs. Carrie Grover of Gorham, Maine, in 1941. Mrs. Grover's song is about a terrible storm at sea and the British ship that was nearly destroyed in the Bay of Biscay-O.

-Joe Offer-