As a Venetian friend told me soon after we moved here, "There are two Venices, one you see on foot, and the other you know only from a boat."
In Venice: The Tourist Maze, Robert C. Davis and Garry R. Marvin put it this way:
Enclosed and walled in rather than scooped out, canals have primacy in Venice, even when they have been whittled down to the narrowness of alleys by competing palace builders: the waterscape of the city is, paradoxically, its bedrock. Even with a good many of them now filled in [a favorite activity of the Austrians in the 19th century], they still represent the most direct way to reach most parts of Venice; unlike the contorted maze of calli, campi, and bridges just above them, they generally make sense, at least to those who have a boat handy to take advantage of them. Which is... to say that they make sense to Venetians, and indeed the canals of the city, or more precisely, getting around on those canals, could reasonably be called the last backstage left in Venice, the final spatial possession of the Venetians.It should probably be noted, though, that this book was published in 2004, and since that time even this "final spatial possession of the Venetians" has become less exclusively their own. One spends years learning about the city's waterways and observing others in their boats before making one's own timid first ventures into the narrow rii, and you shout out the traditional warning as you approach a tight blind right-angle, receive no reply, idle into the turn and--encounter a pod of kayakers in town for the day. My hope is that the number of kayak tours and kayakers won't--like every other tourist venture in Venice--be allowed to get completely out of control.