Alistair Magowan
BBC Sport in Rio

Image source, BBC Sport

Somewhere out there Keri-anne Payne is going for marathon swimming gold but this is definitely a sport where you need a big screen to guide you through. 

There's a decent crowd forming, but with a flotilla of patrol boats surrounding the swimmers the opportunity to see them is brief, and with a section of the beach closed, some locals are miffed that their morning run has been cut short.

By the way, the battleship in the distance hasn't been brought in for this event, it's been there ever since the Olympics started. I'm undecided whether it's reassuring or not! 

Image source, BBC Sport

Lots of races taking place on the track, but there's a medal at stake in the field.

It's the women's hammer throw, and could British record holder Sophie Hitchon get among the medals?

The undisputed favourite for gold is Poland's Anita Wlodarczyk, who has recorded each of the top seven all-time throws... but after her? Not a lot to choose between the other 11 finalists.

Briton Hitchon goes ninth and we'll keep you posted on her progress.

Coming up in a few minutes is the women's omnium scratch race - that's race one of six in the event - and it's 10km. Laura Trott is going for her fourth Olympic gold medal.

Nick Hope
BBC Sport in Rio

Good to see all of the GB pool swimmers down on Copacabana today to support Keri-anne Payne's medal bid.

Hannah Miley tells BBC 5 Live it's an "amazing" race to watch, but "too far" for her to consider.

She also reveals she was one of the nine GB swimmers to have their bags stolen from the athletes village shortly after arrival from the holding camp in Belo Horizonte.

"It's really disappointing because it had most of my kit in that bag and, although I've had some items replaced, a lot of them are the wrong sizes as they don't have many supplies."

Mark Cavendish: People think the omnium is like a jack of all trades. It's not a heptathlon. It's like a modern pentathlon... with six events. 

Image source, reut

Adrian Moorhouse
1988 Olympic 100m breaststroke champion on BBC TV

It's looking very difficult to bridge this gap now. The lead pack are a long way in front. Keri-Anne Payne is leading the chasing pack but with only about 10 minutes to go. 

It looks like Van Rouwendaal has got this tied up now.  

It doesn't look like Keri-Anne Payne is going to be able to challenge for a medal here. 

Sir Chris Hoy
Six-time Olympic cycling champion on BBC One

Mark Cavendish is where he needs to be. It's all down to the points race, that's the way he'll want it. They're all on great form. There's five or six who can win it and Mark is definitely one of those.

It's looking like Mark Cavendish will stay in third place of the omnium, confirmation when we get it.

Great Britain's Marcus Ellis and Chris Langridge are under way in the badminton doubles quarter-finals. 

The duo, ranked 22 in the world, have started well against Japan's Hiroyuki Endo and Kenichi Hayakawa, who are ranked eighth. The GB pair have taken the first game 21-19 and they're currently leading the second 6-1.

Woof. Mark Cavendish has the fifth fastest time so far, with one heat to go. We'll let you know what that means for the omnium leaderboard after the final heat.

Here comes Mark Cavendish now.

In heat six, New Zealand's Dylan Kennett actually goes close to Chris Hoy's world record, only 0.2 seconds off.

So Mark Cavendish probably won't be winning this stage of the omnium, unless we see something special.

Image source, Reuters

British Olympic silver medallist Jazz Carlin has joined Andy Jameson and Adrian Moorhouse in the commentary box!

"I wouldn't call myself an open water swimming expert but you obviously want to be in the pack and be ready for the sprint because the last lap is probably going to be very fast.  

"I have been busy since my last race - I've done quite a lot of media, spent some time with my family, I've been to see some cycling which has been amazing to be in Brazil and at the Olympics."

Update on the race - they still have about another 22-23 minutes left, it's quite choppy but we are under the impression these are the conditions Keri-Anne Payne likes. At the last mark she was in ninth place, eight seconds off the lead.

That was hard for GB's Rob Mullett in the men's 3000m steeplechase. It's hot in Rio and the 29-year-old comes in 12th - that's the end of his challenge.

The only Olympic sport in which men and women compete against each other on a level playing field, equestrian has three disciplines: eventing, dressage and jumping.

Dressage, which is the horse dancing one, is today. It takes place on a flat, perfectly level sandy arena.

The official Rio 2016 guide explains it thus: "The goal is that the horse and the athlete reach perfect harmony while executing the course alternating free and mandatory movements, such as walk, trot, gallop and halt. 

"Free movements present special choreographies for each horse and are followed by music. Seven judges assess each performance, giving points from 1 to 10. After being totaled-up, this score generates a percentage, and the rider with the highest rate is the winner."  

The Brits in action today are Carl Hester (15:35 BST), Fiona Bigwood (14:30 BST) and defending champion Charlotte Dujardin (16:40 BST). All three combined with Spencer Wilton for team silver last week. 

Judy Reynolds (14:50 BST) is the first Irish rider to qualify for an Olympic Grand Prix Freestyle event.

All scores from the team competition are not carried over, so riders start from scratch.

The waves are now coming behind them and someone has used the momentum to make a decisive break.

After much deliberation we have been told it's Sharon van Rouwendaal of the Netherlands although our commentators have their doubts - it's hard to tell!. 

Still about 40 minutes left to race so whoever it is has made a move quite early. 

Keri-Anne Payne is in a good position and has managed to find a good spot with a little spot of clear water in front of her. 

Mark Cavendish is going in heat eight of nine, where he'll take on Roger Kluge of Germany.

We're currently in heat three.

GB's Jodie Williams qualifies as a fastest loser and joins team-mate Dina-Asher Smith, who qualified automatically after finishing second in her heat, in securing a place in Wednesday's semi-finals in the women's 200m. 

But Jamaican sprinter Veronica Campbell-Brown, who won 200m gold at the 2004 and 2008 Olympics, is out.

She ran in the wrong lane as she came off the bend in her 200m heat and didn't run a time fast enough to progress either. Double trouble.

"I seem to be having a bit of a problem," said the 34-year-old. "Last year I was having a problem coming off the bend. It's just so weird. I don't understand it.

"It is what it is, such is life."

Gael Suter, 17th overall, is out first on his own. He does it in one minute 4.443 seconds.

It's almost time for Mark Cavendish, who is racing in the men's omnium time trial, that's race four our of six. He's in third overall halfway through the event.

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