The 1960s pirate radio phenomenon was founded on a simple loophole and a cunning understanding of maritime law.
If a ship was moored three or more miles off the British coastline, it was technically sailing in international waters. A commercial radio station broadcasting from that ship - without a licence, on a stolen frequency, and with no intention of paying taxes - was legally untouchable.
The British government, police, Navy, Customs & Excise and Coastguard had no jurisdiction.
By giving airplay to new groups the pirates curbed the dominance of the major labels and made the BBC (which rationed its pop output to a few hours a week) look like a dinosaur.
Pirate broadcasters frequently had to broadcast in atrocious weather while their ships rolled giddily.
The British Government's Marine Offences Act of 1967 silenced all British offshore pirate radio stations apart from Radio Caroline.