I will be in Shanghai for a week in early mid May 2017. Plan on a day each in Suzhou and Hangzhou.

I want to see the gardens in Suzhou and the west lake in Hangzhou, but want to fit in a short trip on the canal in either of the 2 cities. an hour or so would do.
Are there short canal trips running? Which city should I do this in? What times should I do this (given the time restrictions of the other sights)? Thanks for any suggetsions.