Katie Ledecky is about 25m ahead of the field. This is remarkable. She could cross the channel faster than a Dover-Calais ferry!

Greg Rutherford has squeaked through to tomorrow's long jump final, finishing 10th in qualifying, with 12 places up for grabs.

It was genuinely nervy there for the defending champion.

But Super Saturday II remains plausible. Whoop.

This is exhibition stuff from Katie Ledecky! She's going to lap someone in a minute. Jazz Carlin is well in a medal hunt.

Heat three is done and dusted with the Netherlands' Anouk Vetter crossing first.

It's GB's Katarina Johnson-Thompson and Jess Ennis-Hill up next.

Adrian Moorhouse
1988 Olympic 100m breaststroke champion on BBC TV

Katie Ledecky is going to be going for the world record here.

Katie Ledecky is in her own postcode already but Jazz Carlin is moving well into second place for GB.

Will it be another medal in the pool?

One of the events in the pool tonight is the women's 800m freestyle final.

This is a race Great Britain has had success in the past in. We have dived into the archives to have a look back at Rebecca Adlington's victories in the swimming pool in the 400m and 800m freestyle at Beijing in 2008.

Katie Ledecky has already cleared off. She has clocked all 12 of the fastest 12 times in this event. This is truly a race for silver. 

Up goes the white flag. Relief.

Momentary relief, anyway.

Greg Rutherford's jump is 7.90m - that puts him 10th with 12 going through and more to jump.

We're not safe yet, folks.

Jazz Carlin goes for GB in this one. Katie Ledecky should win it by about four or five seconds - but we've had one [sort of] shock already in the pool. 

Here comes Greg Rutherford's final long jump. A foul and he's out.

Rafael Nadal wins his second Olympic gold with partner Marc Lopez as they defeat Romanian pair Florin Mergea and Horia Tecau 6-2, 3-6, 6-4.

Just the third silver medal for Michael Phelps. He'll probably give it to his window cleaner. 

Will there be more medals for Team GB in the aquatics centre tonight?They have two shots at a medal. 

Jazz Carlin - who won silver in the 400m freestyle - takes on world-wrecker Katie Ledecky in the longer 800m (from 02:20 BST) while Ben Proud goes for sprint joy in the 50m at 02:44 BST.

Also in action is Fran Halsall in the women's 50m semi-final at 02:59 BST. 

Image source, Getty Images

Silvers all round! A remarkable finish as Michael Phelps, Chad le Clos and Laszlo Cseh all get silver in an identical time of 51.14!

The not-so-capacity crowd have a reason to give it some as Brazilian Vanessa Chefer wins heat two of the 200m in the women's heptathlon.

It was her big moment - she's not a medal threat - and the crowd lapped it up. Biggest noise of the night.

Lovely moment.

Joseph Schooling turns in the lead! Under world record pace too...

Michael Phelps sucks it in - he's not nailed on for gold they say in the box - away!