It's truly amazing to listen to the AM band in Atlantic Canada. Other than WBZ, there's almost nothing on in middays. Within a few hours of sunrise and sunset, several Boston AMs are heard and maybe WDEA or WGAN Portland. Maybe a NYC station. I remember WBBR 1130 came in sometimes but again, not in middays.
The best AM radio reception I ever heard in my life was driving over the Confederation Bridge between New Brunswick and Prince Edward Island at night. It's 8 miles long over the saltwater of the Northumberland Strait.
I believe there are still two AM stations in the Maritimes, one in Nova Scotia and one in New Brunswick. But when I was there listening in my car they didn't stop my radio when I hit the scan button.
In New Brunswick, there's CKHJ on 1260 in Fredericton with a terrible, directional signal, which mainly exists to feed two FM rebroadcasters that would be called translators in the U.S. And does CFBC still exist at AM 930 in Saint John? Last I heard it had downgraded from its former 50kw signal to 2kw day, 150 watts night with a Country music format.
In Nova Scotia, I think CKAD Middleton remains as the last AM station on the Annapolis Valley Network, at 1 kw. And CBC Radio 1 is on both AM & FM in Sydney with the 1140 signal retained to reach outlying areas that the FM doesn't cover.
But your point is still valid. There are almost no AM stations left broadcasting in Atlantic Canada, and lots of saltwater around, which makes it a very interesting place for AM DXers.