Hello Beth,
Been diving for 20 + yrs. Did my basic in the Crowsnest pass lakes and took my advance up your way in Jasper. Very awsome hobby, also what really kick drove me into doing salt water aquariums.
Try the Riviera Maya just south of Cancun.
You can also take a 30 min ferry over to Cozumel. Very, very good diving. A good range of difficulty for any diver. I stayed on the Maya side for the cost and more things to see and Cozumel is still close. Someone is always running specials for trips down there.
cheers, Mike