In the British Isles the tidal flows are from the SW Corner along the the South Coast. On the diagram this would be right to left, so the place to search is point B. This is valid for Swanage, Weymouth and Tor Bay. If the bays of the North East are examined then the flow is from the North Eastern corner of Scotland and on the diagram would be left to right and the site would be at A. This is valid for Scarborough and Filey. A quick look at the tide tables of ports either side of the bay in question, will soon determine direction if there is doubt. Of course few bays follow the exact symmetry of a diagram so a little common sense is required. Do not forget that blog images can be enlarged by a click of the mouse. In estuarine conditions like Poole Harbour,limited deposition zones can be identified by the concentration of shelly remains in the mud. Please see earlier posts. BD.