Team GB's Olympic swimming target of six medals is within reach, gold-medal winner Duncan Goodhew has told the BBC.
The Moscow 1980 veteran said Rebecca Adlington and Keri-Anne Payne were the stand-out hopes but the the wider women's team could take more medals.
The men's team "hadn't quite taken the step", he added, saying there needed to be a major breaststroke breakthrough.
"The two that are shouting out are Becky Adlington and Kerry-Anne," said the former breastroke champion.
"Who knows, Becky might get lucky on the 400m (freestyle) and the field may not, as they did last time, so Becky may hold her own. But you also see a plethora of chances for the girls to get silver and bronze.
"The men, they haven't quite taken that step yet.
"Yes, it's about ability, yes it's hard work and training, but it's also that they've got to ask the questions, 'Who, me?' and 'Why me? Out of the seven billion people on the planet, why should I be the best in the world?'
"It may be that they haven't got the ability, but if you are in the top 20 - apart from some notable exceptions like [US 14-time gold medal winner] Michael Phelps - when you go into the cooler room, you are one of the eight fastest people in the world.
"You're held there for 40 minutes, it's the most profound feeling in the world but unless you're really ready for that room, it will eat you alive.
"We have got a few chances in men's breaststroke. What really helps is when you have a few people around the same level and they push each other. But there's got to be a major breakthrough. And that's possible."
Breaststroke swimmers Kris Gilchrist and Andrew Willis train alongside each other in Bath and, with Michael Jamieson, are looking to secure two London 2012 places in each of the 100m and 200m events.
Goodhew, who took gold in the 100m breaststroke and bronze in the 4x100m medley at the Moscow 1980 Olympics, is a London 2012 ambassador for Games organisers Locog.
As part of that role he has been working with the British table tennis team on their strategy and performance for the Games.
"Behind it all is that to win, winning has got to be normal, a heritage of winning for Britain," he said.
He has taken up swimming in the Serpentine in Hyde Park, the venue for the Olympic triathlon swim.
And looking forward to the Games, he has tickets to the volleyball and beach volleyball.
He said: "I am really lucky to live in London so I'm looking forward to getting up on the day, having a cup of coffee and walking to an Olympic final.
"The idea of being right in amongst it is really exciting to me.
"The idea of watching beach volleyball (at Horseguards Parade) in that venue where the Queen troops the colour, where Henry VIII built his tennis courts and where I have my earliest memories of St James's Park - I am so excited about it."
The Swimathon takes place in pools across the UK from 27-29 April to raise money for Marie Curie Cancer Care.
Money raised by the public for the Big Splash Mile will be spent in the UK and across the world by Comic Relief.