I have Cawsand Bay descibed as 'Old Sea Song, Arranged by the Editor' in a song book called'The Open Air Song Book' complied and edited by Aurthur Poyser for the The Boy Scouts Association in 1947.

Back to the business of ascribing dates to songs. Perhaps accademics from the world of English Literature and Poetry might have something to say here?

I seem to remember an article in The Jounal of the EFDSS showing how accademic analysis of Morris Dancing suggested an origin ......... i Courtly Dances?