With the ISAF Sailing World Championships due to kick off at the beginning of July in Cascais, Portugal, this really is crunch time for our Olympic aspirants. Publicly the RYA have been intentionally unspecific about the selection criteria for the Olympics in China next year, as they don't want foreign sailors having a go at ‘jobbing' any of our best medal prospects. But you can be pretty sure that performances at Cascais will feature highly in the selectors' considerations.

There is the quandary of what to do with Ben Ainslie. As I write this, his America's Cup team - Emirates Team New Zealand - is about to enter the Louis Vuitton Cup Finals against the Italian team Luna Rossa. Ben is extremely unlikely to be on the boat for the Kiwis, but his contract demands that he be available to the team until they are eliminated from the competition. Part of Ben must secretly be hoping that New Zealand fall to the Italians and that he get an early release from duty.

Even then, Ben would have his work cut out getting in shape for a boat as demanding as the Finn, although if anyone can do it, Ben can. It's unlikely that Ben is going to be judged for his performance in Cascais, though - unless he does the unthinkable and wins it! What's important is to have Ben pitched against Ed Wright when they're both at the height of their powers.

Ed, the reigning Finn European Champion, would certainly be a hot prospect for a medal if he does go to China next year, but he needs to beat Ben on merit. Imagine the pressure that would sit on Ed's shoulders if he were to be sent to the Games without Ben having had a fair crack at selection. Ed would need to win Chinese Gold to prevent a media frenzy of ‘Why didn't they send Ben?' So for Ben's, Ed's and the RYA's sake, one presumes that there is an ‘Ainslie clause' in the selection procedure.

The selectors face similar headaches in the Yngling and 49er classes. A few months ago, I asked a few people in the know, who they thought would come out on top of the Yngling duel between Shirley Robertson's new team and Sarah Ayton's more established team. Off the record, most thought the power of Shirley would prove too much for her former team mates, the two Sarahs - Ayton and Webb - and their new bowgirl Pippa Wilson.

Shirley has been working immensely hard over the winter from her base in Palma, getting up to speed with her new team of Annie Lush and Lucy McGregor. However, results-wise she hasn't proven the match of Ayton's more polished campaign. With Ayton having just won the ISAF Grade One competition in Holland, the newly-renamed Breitling Regatta, you'd have to say it's going all her way. Shirley pulled out of the regatta for some emergency work on her boat - possibly some work on her keel - but it all seems a bit last minute.

With just weeks to the all-important Worlds, if it was anyone else you'd have to write off their chances. However, Shirley's mastery of the technical side of campaigning, along with her ability to turn it on for the big occasion, means she cannot be ruled out. If these last-minute mods to her boat give that slight speed edge that she is looking for, then maybe she can still put up a fight against the team of two Sarahs and a Pippa.

Biggest selection battle of all for the Brits is likely to come in the 49er class. For the past year Stevie Morrison and Ben Rhodes have been the most consistently performing team in the 49er class, earning podium places throughout 2006 and early 2007. A year ago I described them as the ‘apprentices' to the proven ‘masters' of Chris Draper and Simon Hiscocks. Stevie never lets me forget this apprentice tag whenever I see him, although I like to take some credit for getting him to pull his finger out and finally start sailing properly. Anyway, the apprentices have been continuing to apply the pressure on the established performers, and this will be an intriguing contest in Cascais.

I spoke to Chris Draper not long after he got back from a below-par performance in Holland. He was recovering from a disappointing regatta where he finished 20th, while Stevie was a much more solid 4th. It should also be pointed out that in Hyeres a few weeks earlier, Stevie had finished 6th and Chris won the regatta, so it has not all been one-way traffic for the apprentices, but Chris knows he has a big selection battle on his hands.

Last year, Chris and Simon had an inconsistent year but turned on the performance when it most mattered, winning both the Worlds and the Pre-Olympic Regatta. They then took a big break of about three months, knowing that this would be their last long lay-off before the rigours of the 2007 season.

"In the last quadrennium leading up to Athens, we think we peaked a bit early, and so we've been keen to make sure we peak just right for this time round," says Chris. He and Simon won the Worlds in 2003, were second in the 2004 Worlds and then took Bronze in the Olympic Games, which came as a bit of a disappointment for a team with such high aspirations.

As the team has become more experienced, so they have extended their rest periods between important regattas. "It's very hard work getting everything to the top of your game - getting your equipment, your training, your body, your mind to the top level." We've all heard the saying that ‘it's hard getting to the top, but it's even harder staying there'. As someone who has been at the top of the 49er class for more than five years, Chris believes there is a lot of truth to those words. Hence the focus on peaking at the right time.

After taking time out at the end of 2006, the Rolex Miami Olympic Classes Regatta was supposed to be the jump-off point for the Draper and Hiscocks season. It didn't quite go to plan. They just missed the cut for the Medal Race and finished 12th overall, while Stevie and Ben came 2nd overall. "Miami was our first event having only done two or three weeks of sailing in three or four months," explains Chris. "It wasn't the plan to have done as little sailing as we did, but whenever we tried to get anything done, the weather got in the way." The team was rusty, and a boat like the 49er punishes rustiness harder than most. "I got a bit despondent in Miami but then realised it was unrealistic to expect more. We started training hard after that."

One of the things that Chris believes has changed over the past few years is that, while the standard of the very top of the fleet may not have improved that much, the high standard of sailing has extended much further down the fleet. Where in the last Olympic cycle you might expect a regatta win to go to one of five or six teams, now Chris believes there are 10 to 15 teams all capable of winning regattas. Presumably some of that is down to the change of race format, with the Medal Race opening up greater chances of a surprise result. So in the past, where Chris and Simon might have expected to slot into Miami somewhere in the top 10 - even after a long lay-off from sailing - perhaps that's no longer the case now.

Miami was a wake-up call, and Chris and Simon put in some quality time practising before the next major event in Palma, the Princess Sofia Trophy. "We were sailing pretty well but we wrecked our series with a couple of stupid mistakes," admits Chris. "We forgot to sign off after one race which cost us five points on the scoreboard, and then we picked up an OCS in the qualifying series. We would have medalled quite easily, otherwise." So at least they were sailing fast, even if they had got a couple of the basics wrong. But Stevie and Ben won this regatta.

Hyeres Olympic Regatta was a further shot at redemption, and this went a whole lot better for the World Champions. "We came back from a couple of first bad races, then dominated the rest of the series, and even though we had a pretty average Medal Race we still won the regatta quite easily. It felt like we were back on track and everything was working as we'd hoped. We were back sailing very well."

Following on from Hyeres, they took part in an informal test regatta in the World Championship waters of Cascais, and Chris and Simon won the event quite easily against a fleet that included most of the top players. After this, a good result at the Breitling Regatta (formerly known as Spa Regatta and Holland Regatta) would be the icing on the cake, a good way of peaking towards the Worlds in Portugal.

Unfortunately things didn't run to plan. They were testing some equipment which they expected to be very competitive, but which proved to be anything but. With limited time to set up the mast correctly, Chris says they were "low and slow" out of starts and in marginal situations. "Then we picked up an OCS which put us on the back foot. We started trying a bit too hard, which resulted in getting another OCS and generally not doing a very good job of it all. It was quite disappointing to be making these mistakes at this stage of the game."

Still, Chris has a few weeks to allow the mental scars to heal, and already he had rationalised the 20th place finish in Medemblik. "If we'd have won Spa we might have got complacent again. It's come as a timely kick up the arse, and historically whenever we've had a kick up the arse, it's always done us proud," he says. So, what's the goal for Cascais? "Our goal will be to win the regatta. How the other Brits do will be irrelevant. We know we have everything we need to win, we have the skills, we just have to make sure we put them on the playing field at the right time."

Nothing like putting the pressure on yourself, but in a funny way, focusing on winning the regatta rather than beating the other Brits is a way of taking the pressure off. Just as was the case four years ago at the World Championships in Cadiz, getting selected in the 49er probably means winning the regatta. With Paul Brotherton and Mark Asquith breathing down their necks, that's exactly what Chris and Simon did. They sailed their own regatta and just waited to see how the chips fell. As it was, they dominated Cadiz to the extent that they could sit out the final day's racing.

The build-up to Cascais must feel very similar, except that this time their chief rivals are Stevie and Ben rather than Paul and Mark (actually Mark is sailing with a different Paul now, of the Campbell-James variety, and they are also doing very well in the 49er but are unlikely to feature in Games selection). Chris agrees there are similarities to four years ago. "Paul and Mark were always pushing us hard, but I think they only beat us twice in major regattas, whereas Stevie and Ben have beaten us quite a few times.

"But we're feeling good about the Worlds. We've gone about preparing for Cascais in a similar way to Cadiz. We've spent more time sailing there than anyone else. We know we can turn it on for big events, and that's what it takes to win an Olympic medal."