Garmin is the only one that has a license agreement with the Canadian Hydrographic Service. They have the digital data in their blue chart series. The others only have scanned charts. I used to have a Garmin Map76 and it was great, a little slow to redraw and hard to read in bright sun. I now have a Furuno that seems ok, but it is pretty new. Because of the agreement with CHS, I think I would prefer Garmin. Maybe they update periodically, but they can because they have the digital data.