Check out the repertoire of English singers like Walter Pardon and Sam Larner for sea ballads! Have a look in the Greig Duncan Folk Song Collection (Scottish) which has a whole section of sea songs and ballads. Some titles off the top of my head of ballads/songs with a sea theme...
The Golden Vanity Henry Martin William Taylor The Bold Princess Royal The Loss of the Rammillies The Handsome Cabin Boy Edmund in the Lowlands Low Lowlands Sweet William (father build me a boat)