The comedian Stephen Fry led criticism of the BBC's Diamond Jubilee coverage on Sunday, branding it "mind-numbingly tedious" and dubbing a reporter "ignorant".
The corporation drew stinging criticism during the Thames pageant with viewers attacking its "inane" commentary, camera angles and sound quality.
With broadcasters struggling to cope with technical problems caused by the bad weather - including the sound cutting out during musical performances - Fry chose to single out other aspects of the BBC's coverage.
The host of BBC panel show QI's comments sparked an outpouring of criticism on Twitter.
But the BBC defended its coverage. A spokesman said: "We're very proud of the quality and breadth of the BBC's coverage of this extraordinary event."
Fry wrote: "Has the BBC ever presented a more mind-numbingly tedious programme in its history? "HRH the queen" said the first ignorant presenter. HRH?".
His remarks appeared to resonate among his online followers, prompting a clarification of his comments in a further posting.
"Don't get me wrong peeps, I'm not saying this in relation to ER II's jubilee - just expected better of the beeb. Didn't mean to upset anyone," he wrote.
One follower responded: "my mate who loves boats is appalled by BBC coverage - sky certainly better and we saw more pageant and less jubilee babies!!".
Kevin Marsh, a former editor of the Today programme and The World at One, appeared to echo Fry's views.
He wrote: "Am I being over-critical or is the BBC commentary lamentable?"
But he didn't limit his criticism to the BBC:
https://twitter.com/kjmarsh/status/209327738971107328
In a retweet about the BBC, he added: "Why cut away from Queenie's River Pageant to watch that mindless Tess Daly nonsense... scarcely credible."
Other social networkers were equally scathing.
Neil Jeffrey (@SirBlimelyWindy) tweeted HuffPostUK to say he thought there were "factual inaccuracies and amateurish commentary", while Dave Rickard added: "Add the word sycophantic and you've got it".
Another tweeter said: "Are the BBC trying to be quaint and 'British' with their p*** awful coverage?"
And one appeared to give up on the broadcaster altogether, writing: "I think I have had enough inane BBC commentary".
Tory MP for Reading East, Rob Wilson, joined the voices condemning the BBC's jubilee reporting.
He wrote: "Seems we all agree on terrible BBC coverage. Low grade, celebrity driven drivel. How did Beeb get it so wrong?"
Another damning posting from the politician read: "Which is worse, the heavy rain falling on the flotilla along the Thames or the BBC's dreadful coverage of this Royal Jubilee event?"
Austin Mitchell, Labour MP for Great Grimsby, summed up the coverage in similarly disparaging terms.
"One hated Thames Armada. No Navy left so hordes of tatty boats. Queen freezing, BBC 5Live and TV commentary pathetic. A disgrace," he wrote.