By Martin Gough
BBC Sport at Eton
Steve Williams has insisted the Great Britain coxless four have more in reserve to show a packed home crowd for Saturday's World Championships final.
The coxless four have already enjoyed success this year
The defending champions saw off a strong German crew in Thursday's semi.
"This is a once-in-a-career opportunity. Even Matthew Pinsent didn't win at home," said Williams.
"The expectations are for 40,000 people and the lion's share of those are Brits. It's going to be quite a big cheer coming down the last 500m."
Williams, the last survivor from Pinsent's four that won gold in the Athens Olympics, was calm despite his crew losing half a length to the surging Germans in the last quarter of Thursday's race.
"With 1500m gone, no matter what they did in the last 500m it wasn't going to be enough to beat us," he claimed.
"In the last 500 we were probably at 98%. It probably didn't look pretty, we didn't get any style marks but tactically it's the best thing to do.
No one gets a head start in the final for doing well in the semi
"That wasn't our final. For some boats it will have been. For the semi you've got to be careful to save something, not just physically but mentally as well."
The four is one of six Great Britain crews competing in Saturday's finals but of the Olympic-class boats they were the most impressive in their semi-finals.
The men's double of Matthew Wells and Stephen Rowbotham, and the women's of Anna Bebington and Annie Vernon were both the slowest qualifiers.
But a confident Rowbotham said: "It doesn't matter where you qualify in the semi-final. At the end of the day you've got a lane in the final.
"Any boat out there can win it. We know we're one of the stronger boats, we've shown our speed throughout the year and it's just a matter of hooking up our race."
Bebington and Vernon will draw on the experience of winning medals in World Cup events earlier this season - their first together as a double.
"We didn't have our best row. We're not going to pretend that we did. Fortunately it was good enough to get us through and it's a completely new race on Saturday," said Bebington.
"No one gets a head start in the final for doing well in the semi.
"In Munich we won quite easily when we weren't rowing very well, then in Lucerne to get silver took a cracking row of the type we will have to produce on Saturday."