It is likely impossible to outdo Stan Hugill's description here:
If one listens closely to the air of this song it will be noted instantly that the first half is of the tune of the English shanty Fare Thee Well and the second half that of Blow the Man Down. Originally sung, according to H. Jacques, by les baleiniers des mers du Sud (whalers of the South Seas), as its whaling content implies, in later years it became the property of the French Cape-Horners engaged in the Chilean saltpeter trade. It would be the shanty used aboard the ships of the famous Gallic sailing-ship companies, when they were heaving up their anchors for the last time, homeward bound from the Flaming Coast of Chile, scupper deep with saltpeter, nitrate, and guano. The verses here have been bowdlerized a little by Captain Hayet. The third refrain would be given a "hitch" on the oula by an experienced crowd of sailormen.
Hardi! les gars, vire au guindeau
Ch: Good bye farewell, good bye farewell
Hardi! les gars, adieu Bordeaux!
Ch: Hourra ! oh! Mexico!
Au cap Horn il ne fera pas chaud
Ch: Haul away, hé! Oula tchalez
A faire la pêche au cachalot
Ch: Hal' matelot, hé! ho! hisse hé! ho!
Plus d'un y laissera sa peau
Adieu misère, adieu bateau!
Et nous irons à Valparaiso
Où d'autres laisseront leurs os
Ceux qui r'viendront pavillon haut
C'est premier brin de matelot
Pour la bordée il seront à flot
Bons pour le rack, la fille, le couteau
Hurrah, me bullies, heave the capstan O!
Ch: Goodbye fa-re-well, goodbye fa-re-well
Hurrah, me bullies, farewell Bordeau!
Ch: Hourra, O Mexico!
At Cape Horn it won't be so hot,
Ch: Haul away-hey! Oula tchalez!
Fishing, me boys, for the big cachalot.
Ch: Haul away, John, oh, haul away O!
More than one will lose his hide.
Goodbye to the drudgery, goodbye to the ship.
Then we'll be bound for Valparaiso,
Where others of us will leave our bones.
But those who return with the flags flying high,
Each sure will be one hell of a guy.
For a spree ashore they'll always be ripe,
Just the chaps for the rum, the gals, or the knife!