23. A Matter of Course: Seamarks and Haven-Finding
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23 A Matter of Course Seamarks and Haven-­ Finding He [the competent navigator] knows the value of signs, both regular accidental and abnormal, of good and bad weather; he distinguishes the regions of the ocean by the fish, the color of the water, the nature of the bottom, the birds, the mountains, and other indications. —Mu’allim (Sanskrit: Pilot in the Arabian Sea), AD 434 The terms “way-­finding” and “haven-­finding” refer to the art of traveling toward and locating the specific destinations that one is seeking and include the celestial navigation discussed in chapter 22. In the present chapter, the emphasis is on what is known as adventitious or sec­ ondary aids—noncelestial, noninstrumental methods of ascertaining one’s general location and direction when at sea—and the methods of detecting land when approaching it but still out of sight, by means of of­ ten-­ minute yet telling changes in the environment that go unnoticed by the uninitiated. As the German historian of European water­ craft Uwe Schnall put it, like other premodern sailors, “Seamen of the Middle Ages were trained to observe not only weather conditions . . . but also the slightest change in their surroundings, to a degree which is unthinkable in the present technology-­dependent world.”1 The navigators of times past, with far less other knowledge to master and with far, far fewer distractions of the types that divert humans today, took a passionate interest in these matters and used much of their capacious human memories to build enormous reservoirs of practical marine, atmospheric, and stellar lore. Flightiness: Following the Birds From time immemorial, the movements of birds have been used as indicators of the direction of land. First, the routes of seasonal terrestrial migrants give clues that land lies in the directions from and toward which birds come and go over the waters. For instance, vari­ ous shorebirds that breed in the far north spend their winters in Indonesia and Australia, returning to Alaska and Siberia via Taiwan, the Ryukyus, Japan, the Kuriles, and the Aleutians, a route that has been suggested as the itinerary of initial or otherwise early discovery and settle- Seamarks and Haven-Finding / 247 ment of America by watercraft-­ borne Asians. Likewise, the Belau and Caro­ line Islands of Micronesia are linked to Japan, the Ryukyus, and the Philippines by the Asiatic-­ Belau Flyway; and the Japanese-­ Marianan Flyway runs from Kam­ chatka through Japan, the Bonin, Volcano, and North Mariana Islands, and on south­ west­ ward, southward, and southeastward into the other Micronesian island groups. Additional avian migration routes crisscross the Pacific island world and on occasion were followed by Polynesians seeking new lands. Some Pacific golden plovers migrate round-­ trip from the Aleutians to the west­ ern islands of the Hawaiian chain, down that chain to the Big Island, and south via the Line Islands to East­ ern Polynesia. Other plovers seek out islands in the Marshalls, Gilberts (Kiribati), and Ellises (Tuvalu). Since it appears that most migrating birds orient themselves by sensing Earth’s magnetic field, sailors who followed such migrants were, in a sense, employing an avian magnetic compass. The student of Polynesian sailing Edward Dodd observed, “migratory birds were . . . an indication, nay, they were a proof positive that land lay in the direction in which they flew,” and pointed out that once a voyager ascertained their vector, he could correlate that vector with a star path and be able to sail in the correct direction even if the migratory stream ceased.2 The southward migrations of long-­ tailed cuckoos and bob-­ tailed godwits are said to have led Kupe—the founding navigator from Raratonga—to New Zealand some eight centuries ago. The return migrations of plovers and/or those of the bristle-­ thighed curlew may have led Tahitians to Hawaii.3 Knowing that plovers require land, Polynesians concluded that if birds could cover a distance in a single flight, they themselves could certainly cover it in a large canoe. After their first success, they soon would have been following bird migrations in every direction, until all of the islands to which these birds migrated were found. In fact, an old Tuomotuan chant goes, “Mine is the migrating bird winging afar over remote oceans, / Ever pointing out the sea road of the Black-­ heron. . . . / It is the road of the winds coursed by the Sea Kings to unknown lands!”4 The Chinese also used migrating birds as guides.5 In the Atlantic world, great flocks of waterfowl...