Dina Asher-Smith broke the British record in finishing fifth in the world final last year. She will have high hopes of becoming Britain's first finalist in the women's event since Abi Oyepitan in 2004. She goes in about six minutes in heat five.

A reminder...

Here's a rundown (pardon the pun) of Team GB athletes competing in the morning session in Rio: 

Women's 200m heats

13:54 (BST) Dina Asher-Smith goes in heat five 

14:06 Jodie Williams in heat seven

Men's steeplechase heats

14:25 Rob Mullett goes in heat one

Women's hammer final

14:40 Sophie Hitchon

Men's 400m hurdles heats

15:56 Sebastian Rodger in heat four 

16:03 Jack Green in heat five

In the evening session we'll have:

Men's 110m hurdles heats

00:56 Andy Pozzi is in heat three

01:12 Lawrence Clarke in heat five

Women’s Discus Qualification 

01:50 Jade Lally

Women’s 400m Hurdles Heats

02:10 Eilidh Doyle in heat six

Andy Jameson
BBC commentator and former British Olympic swimmer

It's quite interesting - if you are in a beach short here, you are definitely a foreigner. The men here love their budgie smugglers. 

American swimmer Ryan Lochte was saying he wants to bring back the "banana hammock", as he calls it. 

World champion Dafne Schippers wins heat one of the 200m in 22.51 seconds.

"I feel better than I did before and I'm much happier with this one," said the Dutchwoman.

"My 100m was not so good but my body is very good and I know that I can run the 200m very good. I now get ready for the final."

Adrian Moorhouse
1988 Olympic 100m breaststroke champion on BBC TV

This referee is power mad! He is just waving his arms around for the sake of doing it. 

We pass the 'feeding station' where a bunch of people - and I'm not exaggerating - are stood on a high balcony of sorts holding drinks and gels down in fishing nets for the swimmers to grab.

Keri-anne Payne is self-sufficient, however, she is carrying her own gels on her back. She might have gained a position or two there.

Adrian Moorhouse
1988 Olympic 100m breaststroke champion on BBC TV

Well that's interesting. The two Brazilians come through the first lap in first place in 30.51.6 minutes. We can't hear any screams or shouts from the crowd as they are all spread out on the beach sunbathing.

As we finish lap one, it's a Brazilian one-two at the front with Ana Marcela Cunha and Poliana Okimoto as the front two. Dutchwoman Sharon van Rouwendaal is third.

Britain's Keri-anne Payne is back in sixth, but it's very close. There's not much in it.

The swimmers are near the beach now as we prepare for lap two. We've just seen a bunch of fans watching on the beach. They look like they're having a better time than the swimmers...

Image source, Getty Images

Has the combination of all our swimming talk and a glimmer of the summer made you think about swimming?

Well Get Inspired has a handy guide , externalto start you on your way.

If you want to know what's going on Brit-wise at the velodrome today, here you go:

Women's Sprint - Rebecca James and Katy Marchant

14:00 1/8 Finals

Men’s Omnium - Mark Cavendish

14:21 BST Time Trial (4/6)

20:00 Flying lap (5/6)

21:23 Points race (6/6)

Women's Omnium - Laura Trott

14:59 Scratch race (1/6) 

20:30 Individual Pursuit (2/6)

22:17 Elimination Race (3/6)

Image source, Getty Images

Andy Jameson
BBC commentator and former British Olympic swimmer

We came down yesterday to Ipanema Beach, working very hard to scope out the course *ehem*

Well Andy, we're in an office in Salford. So who's the real winner? 

You, it's you.

Eva Risztov still leads for Hungary, just another 8500m or so to remain at the front...

It was a slightly confusing start to the race. 

The starting pontoon had been blown away by strong winds earlier in the week and had washed up on Copacabana Beach looking like something from an episode of Lost...

This meant the swimmers, as if they don't have to swim far enough, had to swim out to a starting line 200m off the beach. 

Then just a "READYSTEADYGO" and they were off.

Andy Jameson
BBC commentator and former British Olympic swimmer

There is a decent little chop out there now and it looks like the current is taking them a fair way to the left. 

Adrian Moorhouse
1988 Olympic 100m breaststroke champion on BBC TV

She doesn't like to be leading but certainly likes to be somewhere in the front two rows. 

So I'm slightly surprised Keri-Anne Payne is in the middle of the pack. 

Just coming up to 1000m. There is still a loooooonnggg way to go.

Keri-anne Payne, who is wearing a red hat if you are watching live, is out on the right-hand side at the moment. A few of the swimmers have started to drop back. We're about 12 minutes in, so maybe 10% of the way through.

Who are Keri-anne Payne's main rivals likely to be in the Rio water? France's Aurelie Muller is the current world champion and favourite.

Six-time world championship medalist Ana Marcela Cunha and Poliana Okimoto are from Brazil so will have plenty of backing.

Italian Rachele Bruni and Muller shared European Open Water Swimming Championships gold last month after a photo finish could not separate them. Sharon van Rouwendaal and Xin Xin could also be in contention.

Eva Risztov, the 2012 champion, is leading at the moment.  

Image source, Getty Images

Keri-anne Payne, who was brought up in South Africa, is used to open water conditions, which could suit her in the Atlantic. She's tried to prepare herself for all kind of conditions.

Some of the other swimmers might be more used to less choppy waters. Although conditions are good so far off Copacabana.

Payne is right in the mix at the moment.