White Marlin was due to run at Flemington on Anzac Day, but racing was called off in Victoria that day following the death of jockey Dean Holland in a race fall at Donald the previous day.
Waterhouse said the transfer of the meeting to Pakenham was not ideal. "Things were out of our control," Waterhouse told RSN. "We had to go away from the much bigger track, which would have suited him better.
"There were six-and-a-half kilos between the winner and White Marlin and Jordan (Childs) might have been a little bit conservative in the middle stages which gave the other horses time to have a breather and he was stepping back in trip instead of going up.
"This is a true out-and-out stayer and one thing he does exceedingly well, is stay."
Waterhouse has seen White Marlin improve mentally in his time with the stable and was impressed with a recent piece of work the gelding produced.
"He bounced off the track and he looks good. He's on the up. He's very strong, physically and mentally he's improving with maturity. He's a really exciting horse."
Victory on Saturday will see White Marlin join stablemate Goldman, winner of the Roy Higgins in March, with a ballot exemption into the Melbourne Cup.
Waterhouse said she would then need to map out a program with Bott and the respective owners of the two stayers as to which races, they would like to aim at.
"It was interesting that the winner of last year's Melbourne Cup (Gold Trip) ran in the Caulfield Cup, ran in the Cox Plate and ran in the Melbourne Cup," Waterhouse said.
"Week after week after week and he kept improving every time he ran."
No doubt that will be food for thought for Waterhouse, Bott and connections.