Using Plymouth Song Index, I knew that a version is in Terry L. Kinsey's Songs of the Sea (London: Robert Hale, 1989, pp. 141-142; with music; no source is given). Fortunately I have the songbook. Another index (Brunnings' Folk Song Index, Garland) says a song with that title is in Pocket Book of Poems and Songs for the Open Air by Edward Thomas, which I don't have. Here's Kinsey's version.

SALT BEEF

1. Salt beef, salt beef is our relief,
Salt beef and biscuit bread, oh!
Salt beef, salt beef is our relief,
Salt beef and biscuit bread, oh!
While you on shore and a great many more
On dainty dishes feed, oh!
Don't forget your old shipmate,
Fol-de-rol-de-riddle, fol-de-ri-do!

2. Our hammocks they swing wet and cold,
But in them we must lie, oh!
Our hammocks they swing wet and cold,
But in them we must lie, oh!
While you on shore and a great many more,
Are sleeping warm and dry, oh!
Don't forget your old shipmate,
Fol-de-rol-de-riddle, fol-de-ri-do!

~Masato