The website lyrics are not quite as Grainger published them in the Journal of the Folk-Song Society (May, 1908), p. 241:

Shallow Brown
(Hauling Shanty)

_Slowly, plaintively, and dramatically_

(1) Shallow Brown, you're going to leave me.
Shallow, Shallow Brown.
Shallow Brown, you're going to leave me.
Shallow, Shallow Brown.

(2) Shallow Brown, don't ne'er deceive me. (twice)

(3) You're going away across the ocean. (twice)

(4) But you'll ever be my heart's devotion. (twice)

(5) For your return my heart is burning. (twice)

(6) When you return, we'll then get married. (twice)

(7) I'll not regret I ever tarried. (twice) etc.

My guess is that the "etc." merely reflects the idea - possibly suggested by informant Perring - that one might ad lib in a similar vein as long as necessary. "SB" is the only shanty in Grainger's article that ends this way.

All of Grainger's musical transcriptions are unusually detailed as to the singer's ornaments, variations, changes in volume, and so on.