Trick is most salt tolerant shrubs don't like shade. Maybe big leaf hydragea, American Holly, Eastern Ninebark, Black Chokecherry??

Also I suspect that because of the maple the shade is probably dry shade.

In all honesty, it is difficult to get anything started under a mature maple of any kind, worse if it is a Norway maple. Maples have shallow roots that tend to suck up moisture and nutrients, and their relatively dense shade adds one more issue.

Can you add a photo and talk a bit about your goals? Privacy, blocking wind, beauty? Is this a seasonal home or will you be there all growing season to care for whatever is planted? Perhaps with more information we can come up with a solution that meets your goals.