Mickey Luv Abundant at the moment near Falmouth but find it hard to figure out what it is...Devil's tongue weed?
Gerard Heerebout Isn't it Undaria pinnatifida, Japanese wakame?
Mickey Luv I don't think so as it is red, not brown...
Angela Gall Probably devil's tongue weed, we do get it in the Fal. Is it slippery between your fingers? Forked? Could you press a bit to show the shape?