Some discussion of the 1671 profile map of the coast, showing Seaham

The coastal profile below comes from John Seller's The English Pilot of 1671 and marks Seaham, Easington (Isington) and other coastal towns and features such as windmills in schematic form. The standard for an occupied settlement appears to be a square (church) tower and a number of roofed buildings - irrespective of the size of the settlement or whether there is in fact a church present.
This permits some interpretation of the representation of Seaham. Seaham is the lower settlement, and the upper, visible behind it, presumably Seaton, which should be visible 'above' Seaham from a distance out to sea. Seaton lacks a church, but that reality is subordinated to mapping consistency.
Unfortunately, this also means that no information about Seaham in the 17th century can be learned from the map, except its existence, location and visibility...