The oldest references to this song refer to it as the "Fishes Lamentation" or "Windy Old Weather." Though the earliest recording of the song is in a text collection of chanties in 1910, it is suspected to be much older. The song has been performed by a wide variety of famous folk singers, and it would be difficult to decide on a definitive arrangement of the lyrics.
Several variants of the original lyrics can be grouped into two categories, one with the chorus "Windy old weather, stormy old weather, when the wind blows we'll all go together." One with the chorus "blow ye winds westerly, westerly blow, we're bound to the south'ard so steady she goes." A third version of the lyrics, first recorded by Quadriga Consort on their 2011 album "Ship's Ahoy".
The version sung by the Longest Johns appears to match closely with the Quadriga Consort version, though it bears noting that the version used in Assasin's Creed: Black Flag appears to have been based on the Quadriga Consort arrangement, and several of the Longest Johns members are gamers.
It is sung to the tune of "Blow the Wind Southerly"
These lyrics are based on the version performed by the Longest Johns in their Livestreams.
Come all you young sailor-men, listen to me
I'll sing you a song of the fish in the sea
And it's windy weather, boys
Stormy weather, boys
When the wind blows we're all together, boys
blow ye winds westerly, blow ye winds blow
jolly sou'wester, boys, steady she goes!
Up jumps the eel with his slippery tail,
climbs up aloft and reefs the topsail!
Then up jumps the shark with his nine rows of teeth,
saying "you eat the dough, boys, and I'll eat the beef!"
Up jumps the whale the largest of all,
"If you want any wind, well I'll blow you a squall!"