I hope you don't want to shop them to the authorities ! I think they come in the Tendring area.

I've sung there dozens (possibly hundreds) of times over the last 25 years, and I've never signed a membership form. Perhaps they have got a license now. Have a word with Jon at Thrift Music, as he runs the folk club there. They do of course run many events there during the Folk Festival, and there is also the Shanty weekend during November.