co·tid·al line / kōˈtīdl/ • n. a line on a map connecting points at which a tidal level, esp. high tide, occurs simultaneously.

cotidal line A line joining points at which given tidal levels (such as mean high water or mean low water) occur simultaneously. The lines are shown on certain hydrographic charts. The same information is contained in tide tables, where the data are given as differences from the times of high or low water at a ‘standard port’.

cotidal line A line joining points at which given tidal levels (such as mean high water or mean low water) occur simultaneously. The lines are shown on certain hydrographic charts. The same information is contained in tide tables, where the data are given as differences from the times of high or low water at a ‘standard port’.

cotidal line Line joining points at which given tidal levels (such as mean high water or mean low water) occur simultaneously. The lines are shown on certain hydrographic charts. The same information is contained in tide tables, where the data are given as differences from the times of high or low water at a ‘standard port’.