I love my Garmin. Not only do I use mine for "land and sea", but for "air" too, with my plane!!! I use the color 76CSx...dang thing even floats if you drop it overboard!
Ones like the Garmin 76CSx are in the Marine category and I don't think it does Canadian water detail but it does US waters. I'm also interested in one that does US and Canada because I live in NY near Buffalo and also have a house in Canada and a cottage in northern Ontario so I'm really interested in both water systems.