Tidal Stream Atlas 256 covers the Irish Sea and the Bristol Channel.Tidal stream atlases show, in diagrammatic form, the major tidal streams for selected waters of NW Europe. They show, at a glance, both direction and rate of tidal streams at hourly intervals by careful and accurate use of graded arrows. They also display mean neap and spring tidal rates in tenths of a knot. They include diagrams to assist you to calculate the tidal stream rate for your required day.