This is my feeble attempt to show where the "Sarnau" or causeways jut out for various distances under Cardigan Bay. Land is shown in green, shallow water in light blue, and deeper water in dark blue. Sarn Badrig is the largest, covering a large area north of the Mawddach estuary, Sarn-y-Bwch extends from the Dysynni estuary, and Sarn Cynfelyn/Cynfelyn Patches can be seen south of the Dyfi estuary.