In which film did Russell Crowe play royal navy captain Jack Aubrey?
He was Captain Jack Aubrey in Master and Commander: The Far Side of the World (2003), directed by Peter Weir.
When did the Royal Navy switch from coal to oil?
As far as I can tell the Queen Elizabeth class battleships (commissioned in 1915) were the first warships the RN had that were all-oil-fuelled (it had been promulgated by Fisher and Churchill, and the conversion to an all-oil fleet was largely completed by the end of WW1 (1918).
Why is the royal navy the senior service of the armed forces over the Army?
The Royal Navy is known as the senior service over the British Army and Royal Air Force because it has been in existence longer.