[Sidenote:  Three geographic stages of maritime development.]

The size of a sea or ocean is a definite factor in its power to attract or repel maritime ventures, especially in the earlier stages of nautical development.  A broken, indented coast means not only a longer and broader zone of contact between the inhabitants and the sea; it means also the breaking up of the adjacent expanse of water into so many alcoves, in which fisherman, trader and colonist may become at home, and prepare for maritime ventures farther afield.  The enclosed or marginal sea tempts earlier because it can be compassed by coastwise navigation; then by the proximity of its opposite shores and its usual generous equipment with islands, the next step to crosswise navigation is encouraged.  For the earliest stages of maritime development, only the smaller articulations of the coast and the inshore fringe of sea inlets count.  This is shown in the primitive voyages of the Greeks, before they had ventured into the Euxine or west of the forbidding Cape Malia; and in the “inside passage” navigation of the Indians of southern Alaska, British Columbia, and Chile, who have never stretched their nautical ventures beyond the outermost rocks of their skerry-walled coast.

[Sidenote:  Influence of enclosed seas upon navigation.]

A second stage is reached when an enclosed basin is at, hand to widen the maritime horizon, and when this larger field is exploited in all its commercial, colonial and industrial possibilities, as was done by the Phoenicians and Greeks in the Mediterranean, the Hanse Towns in the Baltic, the Dutch and English in the North Sea.  The third and final stage is reached when the nursery of the inshore estuary or gulf and the elementary school of the enclosed basin are in turn outgrown, and the larger maritime spirit moves on to the open ocean for its field of operation.  It is a significant fact that the Norse, bred to the water in their fiords and channels behind their protecting “skerry-wall,” then trained in the stormy basins of the North and Irish Seas, were naturally the first people of Europe to cross the Atlantic, because the Atlantic of their shores, narrowing like all oceans and seas toward the north, assumes almost the character of an enclosed basin.  The distance from Norway to Greenland is only 1,800 miles, little more than that across the Arabian Sea between Africa and India.  We trace, therefore, a certain analogy between the physical subdivisions of the world of water into inlet, marginal sea and ocean, and the anthropo-geographical gradations in maritime development.