The Montreal area supports a number of ferries for bikes and pedestrians only. These operate in the summer months only, and even then are restricted mainly to recreational times—weekends and holidays. They are operated by local boating operators and supported in part by the recreation budgets of some local municipalities.
I've not yet had time to use any of these, but here is a list of the ones I know about, as of summer 2017. (Some of the websites are only available in French.)