The New "Sea Clock" tidal clock is a device that will accurately indicate tidal movements anywhere in the world. Just set it to your local tide movement, and the quartz movement will indicate tidal flows at any time of the day. Great for the angler who relies on tides for optimum angling performance, or the marina who needs to co-ordinate a high tide with a boat launch. Eliminate having to rely on late newspapers for your tidal information. A must for guides! Each set includes detailed instructions and a explanation on tidal movements.