The Library and Archives Canada website recently digitized and made available on its website the 1919-1924 ocean arrivals documents.
The database is a bit difficult to use, but the resource is valuable regardless. There is some introductory material about how to use the database that you should read before you start to browse.
You can find the website at http://www.collectionscanada.gc.ca/genealogy/022-908.004-e.html
And you can read Dick Eastman's newsletter article about it at http://tinyurl.com/2fdn7wc