Sailor Boy is a traditional ballad listed as The Faithful Sailor Boy [Laws K13] and by Meade as Sailor Boy's Farewell. It was first recorded by Gid Tanner of Skillet Licker fame in 1924. Vernon Dalhart's 1925 version titled "Sailor Boy's Farewell" was popular.

Here's info from the ballad index:

EARLIEST DATE: 1859
FOUND IN: US(MA,SE) Ireland Britain Canada(Mar)
REFERENCES (10 citations):
Laws K13, "The Faithful Sailor Boy"
Doerflinger, p. 164, "The Sailor Boy" (1 short text, 1 tune)
SHenry H543, p. 103, "The Sailor Boy" (1 text, 1 tune); also probably H678, p. 89, "The Irish Soldier Boy" (1 text, 1 tune)
Ranson, pp. 32-33, "The Faithful Sailor Boy" (1 text, 1 tune)
McBride 60, "The Sailor Boy" (1 text, 1 tune)
Manny/Wilson 68, "The Faithful Sailor Boy" (1 text, 1 tune)
BrownII 111, "The Faithful Sailor Boy" (1 text plus mention of 3 more)
Chappell-FSRA 33, "Sailor Boy" (1 text)
Fuson, pp. 61-62, "The Soldier Boy" (1 text)
BROADSIDES: NLScotland, L.C.Fol.70(64a), "The Sailor Boy," Poet's Box (Dundee), c. 1890
Notes: G. W. Persley has been listed as the author of this piece, but the song appears older.
The Sam Henry text "The Irish Soldier Boy" lacks many of the elements of fuller versions of this song, and also has a slightly different form. But it has so many elements in common with Laws K13 that I think it must be listed here. If it isn't Laws K13, it's swallowed several verses whole.

SAILOR BOY- Carter Family

'Twas on one dark and stormy night
The snow was on the ground
The sailor boy was at his post
His ship was outward bound.

His sweetheart standing by his side
She mourned a bitter tear
Though as he pressed her to his side
He whispered in her ear

"Farewell, my own true love
This parting gives me pain
And you will be my guiding star
'Til I return again!"

"And then I think of you, my love
While storms are raging high
Then, oh sweetheart, remember me
Your faithful sailor boy."

"Twas sad to say the ship returned
Without the sailor boy
For he had died while on the sea
His flag was held most high

And as his shipmate steps on shore
To tell that he was dead
A letter that he gave to her
These words it sadly read

"Farewell, my own true love
On earth we'll meet no more
Though may we meet in heaven above
Where parting is no more!"