There are different types of eclipses and they are over oceans most of the time. Only about half of eclipses are total, the other half are annular where part of the sun is still showing around the moon since the moon's orbit isn't a perfect circle.

The big news about this one is that since it is through the middle of North America it covers all 48 of the continental states in the US which is pretty rare.

So yeah, they aren't uncommon, but there are uncommon in specific locations.