Waterhouse makes no secret of her disappointment at finishing third in the 2009-10 Sydney trainers' premiership which she has won seven times and been runner-up on seven other occasions.
Over the past few seasons, her biggest successes have been with sprinters and milers and to put that right she sent husband Robbie to New Zealand to find genuine stayers.
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That method worked in the past when Robbie selected a succession of tried stayers including Electronic, Hula Flight and In Joyment, winners of the Metropolitan Handicap (2400m) in the 1990s.
The result this time around was the addition of Descarado and Herculian Prince to Tulloch Lodge.
After running second to Shoot Out in the AJC Australian Derby in the autumn, Descarado lifted to another level to win the Caulfield Cup a couple of weeks after Herculian Prince took out the Metropolitan.
"Sometimes you lose direction which I did last year," Waterhouse said.
"I had a break on an overseas holiday and refocused myself and where I wanted to go.
"I sent my husband to find me a Cup horse.
"It's a race everyone wants to win and I've had quite few attempts and finished second a couple of times.
"Descarado and Herculian Prince have proved they are stayers and Descarado has won on ground from fast to heavy.
"There will be no problem with the 3200 metres or with (Oaks winner) Once Were Wild who also runs in the Cup."
Race jockey Nash Rawiller put Descarado through his paces at Flemington on Tuesday morning while Once Were Wild retired to the solarium after her workout.
The mare has thrived on the regime of spending time under heated ceiling lights and will tune up for the Melbourne Cup in Saturday's Lexus Stakes (2500m) with Michael Walker aboard.
Descarado goes up against Bart Cummings' superstar So You Think in the Mackinnon and Waterhouse admits it's a tough task.
"He is an outstanding horse, he toyed with the best weight-for-age field in the Cox Plate," she said.
Waterhouse is not dismissing So You Think as a rival over the 3200 metres in the Melbourne Cup despite the fact the Cox Plate distance of 2040 metres is the longest he has attempted.
"He's got the best bloke in Australia to train a horse for two miles," she said.
"I might hand my three over for the last few days before the Cup."
