Organisers of the launch of 55,000 firework rockets believe they have set a world record but may have to wait a week for official confirmation.
About 50,000 people watched the record attempt above the Plymouth Sound in Devon on Wednesday.
It took place at the 10th anniversary British Firework Championships, and to qualify all rockets had to be fired within a five-second period.
A Guinness World Records team will decide if the record has been broken.
The attempt was made by Dr Roy Lowry from the University of Plymouth.
'Science is fun'
A spokesman for his team later said: "It looks like we've smashed it but we'll have to wait and see, we're really pleased."
The record attempt lit up the Plymouth Sound
Fifteen specially-constructed frames laced with pyrotechnic fuses were ignited electronically to challenge the previous tally of 39,210 rockets set by Terry McDonald in the Channel Island of Jersey in 1997.
Dr Lowry said: "We wanted to make sure the 10th anniversary was special and also I think this proves that science can be fun."
He said he had been confident about the pyrotechnic side of the record attempt, although he had had some misgivings about the rainy weather.
After the rockets were fired at 2130 BST, a safety gap of about 15 minutes had to be left before Dr Lowry and his team began the mammoth task of counting how many fireworks did not go off, in order to work out how many did.
"All the evidence has to go off to Guinness in London now. Hopefully then, they'll send us a certificate."
The 10th anniversary championship saw eight previous winners of the annual event compete for the title of British Firework Champion of Champions.
A display by Jubilee Fireworks on Wednesday night was the winner.