Im not sure if anyone else has picked up on this but arent alot of the marine slangs just working class speak? I certainly know of and have always spoken many of the marine words like: Scran,ace,bite,bimble,crack,mankey,sprog,wrap.....
Are these possibly derived from certain working class areas and then incorporated into the marines by people who use these words joining up,or maybe its a case of royals speech rubbing off on others back home?
Bootneck slang is in the main derived from naval slang, with it's roots deep in the past. Bearing in mind Britain is an island, a large percentage of the population used to be involved in trades of the sea one way or another, be it working on ships, in the docks, Navy, whatever. The slang has spread from there into the working class of the past, and some words are still used.
Another reason is the media, people hear these phrases in TV and films and adopt them because they sound 'cool.' Someone posted on here a while back that they were shocked when walking into a petrol garage and bought something, the young lass behind the counter said 'say again' rather than 'pardon' or 'scuse me.