It’s no secret that ‘Blue Planet II’ is must-watch television, but the return of the show has surpassed expectations when it comes to ratings. Since it was first broadcast on Sunday 29 October, episode one of the new series has been seen by a whooping 14.1 million people, when you add those who watched it live to the people who caught up online later, making it the most-watched TV event of the year so far. Prior to this, the biggest TV audience of the year was 11.63 million, for June’s One Love Manchester benefit concert (via the Guardian). The first ‘Blue Planet II’ episode is also the third most-watched programme of the last five years, falling slightly short of the numbers achieved by the 2014 football World Cup Final and last year’s ‘Great British Bake Off’ final. A second ‘Blue Planet II’ instalment was screened on Sunday (5 November) leaving many viewers stunned by one revelation, as Sir David Attenborough explained that underwater lakes exist. The new series is made up of seven episodes and this week’s focusses on coral reefs. Catch up on ‘Blue Planet II’ on BBC iPlayer.