We have some information on the Canadian diving scene. It is likely that a majority of the dive-able sites in Canada are located inshore. Ice Diving is likely to be popular here and most dives will be 'cold-water' ones. The up-shot of this is that the diving here is unlikely to be crowded. Diving with a difference it most certainly is! Arctic conditions in winter, near-tropical ones in Summer!
Canadian, being located in the farthest northern hemisphere gets brutal arctic weather in winter-time. However the summers here tend to be worthwhile and hot.
Resort based diving is unlikely. More likely is club-based activity used the surrounded area to dive from.