It's an edit with added music to whats on the British Pathe website:

Radio Caroline 1965 4.47
Film in two sections. First is a 'travelogue' style look at the River Thames. Second is a look at life aboard the ship that hosts Radio Caroline.This would be what was shown in cinemas




Out Takes/Cuts from CP536 Reel 1 of 2 11.01
Starts with Out Tales/Cuts from Unit 4 plus 2, Caroline Out Takes at 5.22




Out Takes/Cuts from CP 536 Reel 2 of 2 11.00
The middle section of these are Out Takes from the River Thames section




All the Out Takes won't have been used as they are shots of the same places.

Also on the British Pathe website
Pirate Radio Afloat 1.41 1964
Radio on the sea! The Radio Caroline broadcasts from a boat off Harwich.