Fair point about fitting the solo lines given to the tune. The original Roll, Jordan, Roll is already close enough to the chanty form, so why make it harder with those extra syllables? Unless that just happened to be a non-representative verse...or the writer half made it up. It verges on literary poetry. I should think a simple "yes, my Lord" for choruses would sound better to the average chantyman than this silly (to my mind) "topsail halliards lower."

Still, I could fit it pretty easily.

xx-x xxxx x-x- ----
x-x- x-x- x--- ----
x/ xxxx x-xx x-x- ----
xx/ x-x- x-x- x--- ----

"lower" is one syllable to match "[a]shore"