Radio Caroline is definitely an interesting bit of history, they alone survived the Wilson government's attempt to bring offshore broadcasting to an end and carried on for decades on and off despite numerous challenges including a shipwreck. After their original ship went to the bottom of the North Sea they managed to acquire a much stronger ship that was out of service due to the Cod Wars and it's still around today, albeit in pretty urgent need of dry-docking (there's a fundraiser going on for that at the moment). They were eventually subject to an armed raid by the British and Dutch governments in 1989 and while they were broadcasting again shortly after this pretty much destroyed the clandestine shore-based organisation that supported the station, and after that a combined effort of harsher legislation and a grounding on the Goodwin Sands put an end to Caroline's offshore career. As the article says though they're still around today, ironically enough from the old BBC World Service medium wave site on 648 kHz relayed from the ship as well as the usual digital places. You can visit the radio ship too but it's moored out in the sticks on the River Blackwater.

It feels like there's still a bit of interest in unlicensed MW broadcasting in the era of cheap SDRs; I wish Ofcom would open it up to hobbyists more legitimately, the few remaining British MW stations are due for the chop soon and it'd be a better use than just letting the band fall silent in my opinion.