Good morning and welcome to Sports Mole's live coverage of day one of the Olympic swimming.
London's stunning Aquatics Centre will play host to a range of events today, including Men's and Women's 400m Individual Medley, Men's 400m Freestyle, and Women's 4x100m Freestyle Relay.
Among the highlights is the hotly anticipated contest between Michael Phelps and his compatriot Ryan Lochte in the Men's 400m Individual Medley.
Phelps earned a record eight gold medals at Beijing 2008, and has 14 to his name overall, but has seen increased competition from Lochte in recent events.
Elsewhere, Team GB's hopes rest in the shoulders of Hannah Miley in the Women's 400m Individual Medley, and Ellen Gandy and Fran Halsall in the 100m Butterfly.
21.01That's all from us here today, but do join us tomorrow for the men's 200m freestyle, the women's 400m freestyle, and much more. Thank you for reading!
20.57To top off our evening, Australia have won the gold in the women's 4x100m freestyle relay. Commiserations to Team GB in fifth place.
20.44Well swam Jamieson. The Brit takes third place behind Sprenger in first and Titenis in second, but he's not quite quick enough to make the final.
20.42A big shout out to the USA's Eric Shanteau, who bounced back from testicular cancer to compete today. A true inspiration!
20.40Second heat is coming up, and we have home interest in this one with Craig Benson and Michael Jamieson set to race. Both are outsiders to make the final, though.
20.38Cameron van der Burgh puts in a majestic performance to secure an Olympic record time of 58.83 in the first heat!
20.34It's the men's 100m breaststroke semi-final up next, and this is sure to be a close one.
20.21Gold medal to China! Shiwen Ye smashes the world record with a time of 4:28.43
20.17It's Hungary's Hosszu in the lead, and Miley is off the pace, but we've a fair way to go yet.
20.13So more than a few shocks so far, and disappointment for Team GB, but Hannah Miley is up next in the women's 400m individual medley. She's our best hope for a medal tonight!
20.00Yang Sun has just become the fist Chinese man to take gold in the men's 400m freestyle. Go on my Sun!
19.54Halsall was some way behind the fastest swimmer of the phase, Sarah Sjostrom of Sweden, but progresses as the seventh quickest, nevertheless.
19.52We've just had the women's 100m butterfly semi-final, and the good news is that Team GB's Fran Halsall has qualified for the final.
19.38Yes! Lochte is short of the world record but he is our new Olympic champion.
19.37He's on for gold without a doubt!
19.36Lochte bursts into freestyle, and he could be in with a shot at the world record!
19.35Lochte has a significant lead now, and Phelps has fallen back to third. Is he conserving his energy?
19.34Lochte is first to turn, Phelps is second, followed by Chad le Clos of South Africa.
19.33We're under way! All eight make a strong start!
19.32And the world record holder Phelps is last to join the party.
19.30Horihata is first out, followed by Fraser-Holmes.
19.28If Phelps wins tonight, he'll be the first man to win a race for the third consecutive Olympics. No pressure then!
19.26Phelps will be swimming in lane eight, how about that? Everyone had him down to take centre stage alongside Lochte.
19.25The swimmers are approaching the starting blocks now and the Men's 400m individual medley final is soon to commence.
19.20We'll be under way in ten minutes. Let's hope we see a few less empty seats this evening.
19:17And Japan's Yuya Horihata is certainly a contender for gold judging by his speedy qualifying time of 4:13.09. Australia's Thomas Fraser-Holmes is not to be written off either.
19.15We were backing Phelps earlier, but Lochte was far more convincing during the heats.
19.13It's in this event that legendary Olympian Michael Phelps will take on his great rival and compatriot Ryan Lochte.
19.10There are four gold medals up for grabs here tonight and two semi-finals taking place. No doubt the men's 400m individual medley, which is first on the bill, is the one on everyone's mind.
19.08And that's not all! Team GB made the women's freestyle relay final... just, but who's complaining?
19.04There was good news for Team GB with Hannah Miley booking a place in the women's 400m individual medley final. Fran Halsall, Ellen Gandy, David Carry, Michael Jamieson and Craig Benson also progressed in their respective competitions.
19.02There were more than a few surprises, not least Michael Phelps barely scraping through to the men's 400m individual medley final in eight place, and Beijing silver medallist Laszlo Cseh crashing out.
19.00Welcome back to Sports Mole's live coverage of day one of the Olympic swimming. We've got quite an evening ahead of us following a thrilling morning of pool action.
16.38Sports Mole will be on hand to bring you all the action from this evening's semi-finals and finals from 7pm. Do rejoin us then!
16.36Elsewhere, the British women's 4x100m freestyle relay team narrowly made this evening's finals, so there was good news on that front too.
16.35As I'm sure many of you will already know, there was good news for Great Britain in those events. Both Michael Jamieson and Craig Benson made the semi-finals!
16.34Apologies! We were hit by technical difficulties just as the men's 100m breaststroke was reaching its climax!
12:02Benson comes fourth, but with a strong time of 60.04 seconds. That might well be enough to see him through!
12:01We're well into the men's 100m breaststroke now, and in the fourth heat we have Team GB's Craig Benson. Go Craig!
11.47Elizabeth Beisel of the USA wins it, Willmot falls away and finishes in fifth, but her time of 4:38.87 is one to be proud of.
11:45Team GB's Aimee Willmott is up in the final heat. She's looking good in third, and a place in the final is not out of the question.
11:42A time of 4:34.98 for Miley there, putting her well on course for the final. Rice will likely go through with her with only one heat remaining.
11.41A spectacular finish by Miley sees her take first ahead of Australia's Stephanie Rice. The crowd goes wild!
11:40100m of freestyle remains, and Miley is looking good to qualify in second place, but she's digging in.
11:38Miley is on course to at least equal her British record as we approach halfway!
11.37Miley of Great Britain is up now, and the crowd gives her a big cheer.
11.35China's Shiwen Ye beats Hosszu to the finish with a superb time of 4:31.73. Hosszu is also likely to make the final with her time of 4:33.77.
11.31The first of the seeded heats has begun and Hungary's Katinka Hosszu is the one to watch her. She turned in an impressive qualifying time of 4:32.83.
11.29Kim wins the heat with a lifetime best of 4:43.99. Well done to the Korean!
11.27Thi Anh Vien Nguyen of China put in a strong performance to take the first heat with a time of 4:50.32. Seoyeong Kim of South Korea leads in the second.
11.24The women's 400m individual medley is now into its second heat. The one to watch in this event is Hannah Miley in the fourth heat.
11:15Well done, David, a bold swim there!
11.13Sun Yang wins the final heat, going into the final with the fastest time of 3:45.07. But the good new for us Brits is that Carry goes through with him!
11.09So, Gergo Kis of Hungary wins it with a time of 3:46.77, and Britain's Carry comes third 3:47.25. Both times might yet be enough to secure qualification.
11.08We're not sure why yet, but it seems that it was either a false start or failure to touch the side on one of his turns.
11.07That was a speedy heat! Taehwan Park of South Korea won it, but has been disqualified!
11.04We're into the third heat now, and Great Britain's David Carry has stormed into a lead.
11.00The Men's 400m Freestyle is under way now, and Team GB hopeful Robbie Renwick has just recorded a time of 3:46.73 in the second heat, giving him a potential chance of qualifying.
10.49Halsall and Gandy both make the semi-finals in eighth and ninth place, with times of 58.23 and 58.25, respectively.
10.47She looks on course to qualify, finishing in second place. Fellow Team GB swimmer Ellen Gandy is also in course to go through to the next phase with a time of 58.25
10.42The first seeded heat of the Women's 100m Butterfly is under way, and Team GB's Fran Halsall is up.
10.34Women's 100m Butterfly is up next.
10.30le Clos wins it by the narrowest of margins. Lochte takes second place and also qualifies. Phelps scrapes through to the final, taking the eighth podium! Sensational stuff!
10.29Six swimmers in this heat would have to beat Phelp's time to knock him out of the competition. Unlikely at this stage, but not impossible!
10.28Lochte leads at the halfway point, but Chad le Clos of South Africa is less than a second behind.
10.25The final heat commences, and Lochte takes centre stage.
10.24Phelps wins it with a time of 4:13.33, but by his standards, that's not that quick! It puts him at third overall, though, so he's still well on course for a place in the final.
10.23Cseh has a narrow lead on Phelps here, but the American is clearly conserving his energy. Britain's Pavoni is in fifth.
10.20Phelps flies into the lead, followed by Hungary's Laszlo Cseh. You have to feel for Cseh. He's putting in a great performance, but how do you compete with Phelps?
10.20Forth heat under way, and here comes the Baltimore Bullet! Great reception from the crowd.
10.19Hagino wins the heat with a time of 4:10.01 - very quick indeed. Roebuck finishes seventh.
10.17Japanese teen Kosuke Hagino is the pace-setter now. He needs to turn in a good time if he wants to qualify for the finals with the likes of Phelps and Lochte yet to swim.
10.16Roebuck is lagging behind in seventh place going into the backstroke leg. The Briton has it all to do here!
10.13Heat three is under way, and we have Team GB's Roebuck in this one, occupying lane two.
10.12The Belgian Raphael Stacchiotti pips him to the post with a time of 4:16.71!
10.10Luxembourg's Raphael Stacchiotti is in the lead, but it's tight.
10.08The second heat is under way.
10.06Ally wins the first heat with a time of 4:21.32, a comfortable lead over second-placed McKee.
10.04Bradley Ally of Barbados looks like he's going to take this one. He has a good four-second lead going into the breaststroke.
10.01They're off!
9.59The swimmers are lining up on the starting blocks for the first heat. Iceland's Anton Sveinn McKee is the one to watch in this.
9.58This event was a sellout well in advance, but there are clusters of empty seats around the venue. Let's hope they will up in the next few minutes!
9.55We're about to get under way in the Men's 400m Individual Medley. Phelps vs Lochte is coming up!
9.53Roebuck took to Twitter last night to thank his fans for their backing: "Thanks for all the messages of support. Really does mean a lot to know that people are rooting for me and TeamGB and willing us to succeed."
9.50Team GB's Roebuck will swim in heat three.
9.48Phelps will compete in the fourth heat with Britain's Pavoni, while Lochte has been seeded in the fifth.
9.47The heats for the Men's 400m Individual Medley get under way in just over ten minutes.
9.43World records tumbled in Beijing in 2008, but London 2012 will prove to be a greater test of the athletes' abilities. The polyurethane suits that helped swimmers hit top speeds have been banned this time around.
9.39Miley took gold in the Barcelona leg of the Mare Nostrum series last month, a competition where Britain's medal haul was an impressive 29.
9.33There are a total of four gold medals up for grabs today, and Great Britain have a shot at one of them through Hannah Miley in the Women's 400m Individual Medley.
9.31Team GB's hopes in the Men's 400m Individual Medley rest on the shoulders of Roberto Pavoni and Joe Roebuck. They are an impressive duo, but the Americans are clear favourites.
9.27Phelps is extraordinary in every sense of the word. An unusual physique has played no small part in his success. He has a bigger arm span than his body height, and his size 14 feet are backed up by ankles that can extend beyond the point of a ballet dancer!
9.25For what it's worth, our money is on Phelps for 400m gold. This is the final stage of his competitive career, so we can expect him to raise his game.
9.23Thanks to BBC Sport for those quotes.
9.23"I am friends with everyone, I don't have any enemies so I can't say he [Phelps] is. He's my competitor and a great rivalry has built out of our past meets, but we're also great friends and win or lose after the race we'll still be great friends and I hope it stays that way.
"You do have to conserve your energy, but at the same time you have to have fun. I've been doing pretty well balancing the pool and outside stuff.
"Back home people are talking about me and Michael but it's just talk and we'll see what happens."
9.23Lochte: "I'm not going just to swim to beat Michael - he's just one person - there are a bunch of others from around the world and I just have to race and have fun.
"If at the end of the race he is right there with me he is right there with me, but I can't focus on one person.
9.22"I have found that recovery is more important now than it was then [at previous Olympics]. My body is older. Training and everything was perfect leading up to Beijing in 2008. It will be harder for me to recover than before, but the trials gave me an idea of what I'll be up against.
"There will be lots of ice tubs and sleeping and saving emotional energy - it's a very full week and I have to stay on top of it no matter how tired I get.
"Some like to express their feelings in words, or actions, I like to do it through swimming. I have got to where I am through hard work and I'm very happy with my career and what I have done with it and we'll see what happens over the last week of it."
9.22Phelps: " "This is the closure and it's really about how many toppings I want on my sundae - I want to enjoy it.
"Ryan's doing lots of strength training, pushing tyres etc. I have two people who work with me. They put on paper what I do and we have done boxing, weight lifts and they keep it fresh and exciting and new so that we stay interested. Everyone needs something different. For Ryan it's a tyre, or lifting chains, but I don't see myself doing that....
9.20We have some quotes from the American favourites coming up...
9.16Lochte came out on top in last year's World Championships and the US Olympic trials, suggesting that Phelps is in for a stern test today.
9.15Having said that, he has seen increased competition from Lochte of late.
9.12On paper, the legendary Phelps has a vastly superior record. Not only does the Baltimore Bullet have an impressive 14 gold medals to his name, he secured a record eight golds at Beijing 2008.
9.10The Men's 400m Individual Medley is up first, and all eyes will be on the anticipated contest between Michael Phelps and his Team USA rival Ryan Lochte.
9.05Good morning, London 2012 has a lot to live up to after last night's spectacular opening ceremony, but we have quite a day ahead of us at the Aquatics Centre.
