After starting as a Midshipman automatically a Naval Cadet will be promoted to the rank of Sub-Lieutenant usually while still in training. This happens at around the 12 month point.
After a naval officer has finished training and moved to an operational ship or shore based establishment they will be promoted to a Lieutenant, as with all ranks they will need to have shown the right attitude and have performed to a high standard.
A Lieutenant Commander is normally in charge of a department on a large ship or on a shore base. Lieutenant Commander’s may be Executive Officers and also they may find themselves Commanding Officers of some of the Royal Navy’s smaller units.
A Commander in the Royal Navy will command a warship or submarine, a shore based establishment or an elite Fleet Air Arm squadron. Commanders also serve as staff officers and take up roles with the Ministry of Defence; many will serve on exchange programs and work with foreign forces. Commanders will also serve in headquarters.
Captains in the Royal Navy will command large vessels and also hold senior positions in various establishments on shore.
A Commodore will be the Commanding Officer of a large Royal Navy Unit.
A Rear Admiral is an officer of flag rank; as such they have their own flag flying on a ship or headquarters and are responsible for an entire capability within the Royal Navy.
Vice Admirals are senior officers in the navy and help implement changes in policy within the navy and also defence policy.
An Admiral is the highest rank in the Royal Navy and is equivalent to a General in the British Army.