I thought that the Maid On The Shore was a mermaid.

There is If I Was A Blackbird, although the lady in question sings about wanting to follow her true love to sea.

There is Three Fishers, as sung by Stan Rogers on For The Family, although the women aren't out on the boats.

Banks of Newfoundland mentions a lady on board who tears up her flannel petticoats to make mittens for the sailors. This is the version sung by Chris Foster. (There is another completely different song by the same name.)

The Flower of Serving Men has nothing to do with the sea, but it is a fine song about a woman impersonating a man. Considering its sad and bloody beginning, it's odd that it ends with a joke.