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How
the Wayfinder Locates Land
Photo below: An atoll
appears as a thin black line on the horizon.
 Once
the canoe is in the vicinity of its destination according to the
wayfinder's dead reckoning and latitude measurements, the wayfinder
starts looking for land.
Navigating without
instruments is not a precise science. Poor weather and mental lapses
on a long voyage adversely affect its accuracy. But the wayfinder
need not sail to a destination with pinpoint accuracy to be
successful. Instead , the wayfinder in the Pacific tries to hit a
"screen" of islands, that is, a group of islands that stretches out
on either side of his destination. The longer or wider the screen,
the less likely the wayfinder will miss it. Islands in the Pacific
are seldom isolated; they are usually found in clusters. The Tuamotu
Archipelago stretches 550 miles north to south and 500 miles east to
west; the Society Islands stretches 160 miles north to south and 310
miles east to west; the Hawaiian islands extend more than a 1000
miles across the ocean east to west; the major islands form a
north-south screen of about 240 miles.
Thus while sailing to
Tahiti from Hawai'i, the wayfinder can target a 400-mile wide screen
of islands between Manihi in the western Tuamotus, and Maupiti in
the eastern Society Islands. If the wayfinder can hit any one of the
islands in this target screen, he can reorient the canoe after he
identifies the island and determines its position in relationship to
his destination; if he does not recognize the island and the island
is inhabited, he can ask the islanders where he is and if possible,
get directions to his destination.
While there are
open-ocean gaps between islands in a screen, a wayfinder looks for
signs to let him know the proximity and direction of land even when
he cannot see it. Signs of land include drifting land vegetation;
clouds piled up over islands; the loom above an island created by
sunlight or moonlight reflecting up from the white sand and smooth
water of a lagoon; distinctive patterns of swells created by swells
refracting around and / or reflecting off islands; and seabirds such
as the manu-o-Ku (fairy tern) and the noio (noddy tern), which go
out to sea in the morning to feed on fish and return to land at
night to rest.
The diurnal flights of
such birds are the most useful signs for expanding landfall, since
their flights to and from an island gives a fairly specific
direction to the wayfinder. As the birds leave an island in the
morning, the wayfinder can sail in the direction the birds are
coming from to find land; as the birds return to an island in the
late afternoon, the wayfinder can follow the birds to land.
While a low atoll with
trees can be seen at sea from about 7 -10 miles away, observing the
daily flight patterns of seabirds can indicate the direction of
islands out of sight range. Nainoa Thompson gives the following
estimates of ranges of two seabirds that are the most reliable
indicators of land:
Manu-o-Ku (white tern):
approximately 120 miles (though this bird may stay out at sea, or
fly back to land unseen at night)
Noio (noddy tern): approximately 40
miles
Generally, sighting of
large groups of birds are more reliable signs of islands than one or
two birds stray birds or small groups. (Click
here
for a photo of a large bird pile near Rangiroa Atoll in the Tuamotu
Archipelago. The atoll is faintly visible at the horizon. Hokule'a
was looking for the Tuamotus on the way to Tahiti after having left
Rapa Nui and finding Fatu Hiva in the Marquesas. Tahiti lies about
170 miles to the SW of Rangiroa. December 1999. Photo by Na'alehu
Anthony.)
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