There was general bafflement as the water in the Olympic diving pool turned bright green on Tuesday - just as a British pair were aiming for a medal.
The picture above shows the dramatic change in colouration in the space of 24-hours, prompting Team GB’s Tom Daley, who bagged bronze last night in the pool, to tweet his confusion.
The incredible scenes - unwelcome for Rio organisers who have been fending off criticism over pollution - unfolded as Tonia Couch and Lois Toulson were trying to match Daley and Dan Goodfellow’s heroics in the synchronised platform event.
This is Couch and Toulson heading for the murky green.
The pair, who missed out on a medal after an error in their final dive and finished fifth, admitted they could not see each other under the water. Couch said:
“It’s so green. But, we got a personal best score, so maybe we should ask for a green pool from now on. I kind of liked it.
“As the sun went down it looked worse.
“I couldn’t see you when I was underneath. I was like ‘Lois, where are you?’”
“We can’t do anything about it, so just concentrate on what you’re doing.”
Officials were unable to explain why the Maria Lenk Aquatics Centrehad pool changed colour, but there was speculation the levels of chlorine had dropped and allowed green algae to grow.
Lots of people watching were asking the same question: