In Canada it doesn't work the same as in the US. In the US you can use high power but you need an FCC license. In Canada you can't use anything high powered unless you have a permit or are a professional which requires it (coast guard, police, etc). You can't buy 5 Watt GMRS radios in Canada at all because they're for recreational use only.

My SAR group uses high power VHF hand helds and a VERY high powered base station in a trailer with a 40 foot antenna and something like a 40 mile range...but we have special permission from the RCMP to do so (and use some of their frequencies).