In Canow Kernow, edited by Inglis Gundry, it's under the title "The Robbers' Retreat - The Cadgwith Anthem". It says it was 'Sung by a group of local fishermen at Cadgwith, 1956 and recorded by Peter Kennedy. The foot-note says:
'The singers described this song as "just given to us by the old friends gone by." There was "no music attached to it", but John Henry Jane was said to be "the first man who sang it in this bar".'

It is still sung in Cadgwith and there are still members of the Jane family living there.

Best Wishes
Marion