When I occasionally use the term "maritime" music, it's in reference to chanteys and other songs of the sea. These songs may, but usually don't, come from Canada's Maritime province.

"Celtic" music refers broadly to music from the Celtic lands -- Ireland, Scotland, Wales, Brittany, Isle of Man, Galiza, etc. -- or music played in the styles of those lands. Much of the Maritime provinces' populations are descended from Scottish and Irish immigrants, so it's not surprising that there'd be a lot of Celtic music in their traditions.

Smithsonian Folkways has a new compilation CD coming out next week of sea songs called "Classic Maritime Music from Smithsonian Folkways Recordings." None of the performers on it are from the Maritime provinces. The only Canadian included is the late Alan Mills of Montreal.