Armed Forces & World Wars
British Armed Forces
World Wars
The British Royal Navy
In both world wars the Royal Navy was a huge and complex organisation spread all across the world. It is therefore not surprising that the Navy's rank, profession, trade, pay and related badges structures were complex, and are almost impossible to understand.
It is important to remember that the Navy was divided into branches, sometimes called trades, such as Accounting, Engineering, Medical, and Fleet Air Arm. Ranks within these branches might have their own titles, such as Paymasters (accountants), Artificers (engineers) and Writers (clerks). Normally these titles would be added to their rank particularly for officers, such as Paymaster Lieutenant or Petty Officer Photographer for other ranks (equivalent to Chief Petty Officer), but by no means always. The grades of armourers, for example, were: Chief Armourer; Armourer; Armourer's Mate; Armourer's Crew. The branch was identified by badges worn on the right upper sleeve on the uniform.
The whole system is explained in more detail here:
Ranks, Professions, Trades, Pay & Allowances, and Badges of Rank - June 1942.
Royal Marines use Army ranks, with marines being the equivalent of privates in the Army.