Charley and others are perfectly correct when stating that chanties were not permitted onboard Royal Navy ships. The ships were worked either to direct verbal orders (As in the orders "two, six, heave) or to pipes (Bosun's Calls).

The "Rum, Sodomy and The Lash" thing was a Churchillian quote dating from the early days of last century when he backed Jackie Fisher's naval reforms. These reforms were bitterly contested by Beresford who stated that they (the reforms) were counter to the best traditions of the service (The Royal Navy). To which Churchill responded that the best traditions of the service are founded on "Rum, Sodomy and the Lash" and as such should not be viewed as being of any significant value.

I have not seen the film yet but will definitely go first opportunity I get.

"Spanish Ladies" pre-dates the French Revolutionary/Napoleonic era. I believe goes back to the mid 1700's and the time of Admiral Hawke.