"What is WAAS?"
a detailed description of the WAAS system click
"Does WAAS work in Canada?"
A: Whether your WAAS-enabled GPS can receive WAAS signals depends
on your location. The current WAAS satellites are in orbit over
the equator so may be low on the horizon, or below the horizon from
locations within Canada.
[See next question too!]
"My GPS has WAAS but it does not seem to be improving accuracy.
What gives? "
here for "WAAS Operation: Your Questions Answered"
by Joe Mehaffey & Jack Yeazel