A good number of postcards for sale in areas of high tourist traffic will show a narrow stretch of canal (or more likely rio) running behind old gothic properties and made interesting by a row of highly polished black gondole and their matching blue tarpaulins. As a reminder of the city it’s a misleading image as most visitors will never see this, for during daylight hours the gondola will be earning its owners keep. If you want the shot, then you have to rise early before the vessels and their owners get to work.
Which is not to say that you don’t see narrow rii with rows of small boats threaded along them like charms on a bracelet. Just don’t expect the boats moored behind houses to be quite so romantic. These are the equivalents of the family car.