I've just listened on BBC iPlayer. At one point there is a comment on how the perspective in the song changes, the first verse being from the point of view of a sailor swinging in his hammock, and the last verse from that of Lady Franklin.

Cyril Tawney had a version (I don't know where from) with the second verse forming a link:
And as we neared old England's shore
I saw a lady in deep deplore.
She wept aloud, and she seemed to say
"Alas, my Franklin is long away".

Richard