No breeze drives the ship forward, so dead is the sluggish wind of this idle sea. He [Himilco] also adds that there is much seaweed among the waves, and that it often holds the ship back like bushes. Nevertheless, he says that the sea has no great depth, and that the surface of the earth is barely covered by a little water. The monsters of the sea move continually hither and thither, and the wild beasts swim among the sluggish and slowly creeping ships.[33]

Avienus also has the following:

Farther to the west from these Pillars there is boundless sea. Himilco relates that ... none has sailed ships over these waters, because propelling winds are lacking ... likewise because darkness screens the light of day with a sort of clothing, and because a fog always conceals the sea.[34]

Fig. 1—Map of the Sargasso Sea showing its relation to the Azores, to illustrate its possible bearing on the medieval belief in the existence of lands or islands beyond. Scale 1:72,000,000. (The map is also intended to help in locating the various existing islands of the North Atlantic.)

Aristotle, as cited by Nansen, tells us in his “Meteorologica” that the sea beyond the Pillars of Hercules was muddy and shallow and little stirred by the winds.[35] In early life Aristotle was a pupil of Plato, and, though he afterward developed a widely different method and outlook, it is likely that their information as to this matter was in common, being supplied perhaps by Phoenician and other seamen.

In the passage quoted from Scylax and the first excerpt from Avienus the courses referred to are apparently too near the mainland shore to approach that prodigious accumulation of eddy-borne weeds in dead water which has long given to a great space of mid-Atlantic the name of the Sargasso Sea. But they show that huge seaweeds were very early associated with obstruction to navigation in seafaring minds and popular fancy. Perhaps they may also have suggested shallows as affording beds of nourishment for so enormous an output of vegetation. It would not readily occur to the early seagoing observers that the greatest of these entangling creations floated in masses quite free, though we now know this to be the case. In any event, it is evident that some imperfect knowledge of conditions far west of the Pillars of Hercules had made its way to Greece. Somewhere in that ocean of obscurity and mystery there was a vast dead and stagnant sea, presumably shallow, a sea to be shunned. Gigantic entrapping weeds and wallowing sea monsters freely distributed were recognized, too, as among the standing terrors of the Atlantic.

The Sargasso Sea As the Ancient Atlantis

It would be idle and wearying to follow such utterances through the rather numerous centuries that have elapsed since those early times. When the Magrurin or deluded explorers of Lisbon, at some undefined time between the early eighth century and the middle of the twelfth attempted, according to Edrisi, to cross the great westward Sea of Darkness they encountered an impassable tract of ocean and had to change their course, apparently reaching one of the Canary Islands. Later the map of the Pizigani brothers of 1367[36] ([Fig. 2]) contains in words and a saintly figure of warning a solemn protest against attempting to sail the unnavigable ocean tract beyond the Azores. As will be seen by a modern map ([Fig. 1]), this area includes the vast realm of the Sargasso—a waste of weed, shifting its borders with the seasons but constant in its characteristics in some parts and always to be found by little seeking—one of the permanent conspicuous features of earth’s surface.[37] It is described by a writer in the Encyclopaedia Britannica as nearly equal to Europe in area, a statement hardly warranted unless by including all outlying tatters and fringes of Gulf weed floating free.[38]

It is one of the topics that tempt and have always tempted exaggeration and misunderstandings. The effect on a bright mind of current nautical yarns concerning it is shown by Janvier’s “In the Sargasso Sea,” a narrative almost as extravagant as Plato’s tale of Atlantis, in its own quite different way. One of the more moderate preliminary passages may be cited: