When my father was in the Navy, ca. 1920, he was an engineer & spent most of his time in shipyards. However, it seems that they did put him on a ship one time, and while he was being sick, a real sailor came up behind him and said "If you feel something hairy & round come up, swallow it down quick, because that'll be your asshole."

I have often thought that that has the makings of a song in it, tho I haven't gotten around to it. The chorus would be

    Roll, pitch, yaw,
    Surge, sway, heave!