The effect of subsidence, even on a low coastal plain, is to increase accessibility from the sea by flooding the previous river valleys and transforming them into a succession of long shallow inlets, alternating with low or hilly tongues of land.  Such embayed coasts form our Atlantic seaboard from Delaware Bay, through Chesapeake Bay to Pamlico Sound, the North Sea face of England, the funnel-shaped “foerden” or firths on the eastern side of Jutland and Schleswig-Holstein, and the ragged sounds or “Bodden” that indent the Baltic shore of Germany from the Bay of Lubeck to the mouth of the Oder River.[450] Although the shallowness of the bordering sea and the sand-bars and sand reefs which characterize all flat coasts here also exclude the largest vessels, such coasts have nevertheless ample contact with both land and sea.  They tend to develop, therefore, the activities appropriate to both.  A fertile soil and abundant local resources, as in tidewater Maryland and Virginia, make the land more attractive than the sea; the inhabitants become farmers rather than sailors.  On the other hand, an embayed coastland promising little return to the labor of tillage, but with abundant fisheries and a superior location for maritime trade, is sure to profit by the accessible sea, and achieve the predominant maritime activity which characterized the mediaeval Hanse Towns of northern Germany and colonial New England.

[Sidenote:  Maritime activity on steep embayed coasts.]

Subsidence that brings the beat of the surf against the bolder reliefs of the land produces a ragged, indented coast, deep-water inlets penetrating far into the country, hilly or mountainous tongues of land running far out into the sea and breaking up into a swarm of islands and rocks, whose outer limits indicate approximately the old prediluvial line of shore.[451] Such are the fiord regions of Norway, southern Alaska, British Columbia, Greenland, and southern Chile; the Rias or submerged river valley coast of northwestern Spain; and the deeply sunken mountain flank of Dalmatia, whose every lateral valley has become a bay or a strait between mainland and island.  All these coasts are characterized by a close succession of inlets, a limited amount of level country for settlement or cultivation, and in their rear a steep slope impeding communication with their hinterland.  Inaccessibility from the land, a high degree of accessibility from the sea, and a paucity of local resources unite to thrust the inhabitants of such coasts out upon the deep, to make of them fishermen, seamen, and ocean carriers.  The same result follows where no barrier on the land side exists, but where a granitic or glaciated soil in the interior discourages agriculture and landward expansion, as in Brittany, Maine, and Newfoundland.  In all these the land repels and the sea attracts.  Brittany furnishes one-fifth of all the sailors in France’s merchant marine,[452] and its pelagic fishermen sweep the seas from Newfoundland to Iceland.