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01Exploring by dayDuring daylight hours, you will be able to
make out
points of reference on land such as mountains or large
structures as well as follow the path of the Sun itself.
When
possible, do as the ancient mariners would and stay within
sight of the coast and use these landmarks to guide you.
This
also means youre never too far from terra firma for
supplies.
02Exploring by nightOnce the Sun goes down and the coast is no
longer
visible and given the general lack of visibility
moving closer to the land is not recommended due to the
increased risk of running aground in shallow water and other
dangers like reefs. Instead grab your star charts and look
upwards to make use of the night sky.
2
How to
ANCIENT SEAFARING TECHNIQUESBEFORE THE 12TH CENTURY CE
First invented as a device for divining
as early as the Chinese Han Dynasty
(around 206 BCE), the compass was
adopted for maritime navigation by
the early-12th century CE. However, we
know that many cultures were sailing
well before this so how exactly didthey navigate Earths vast
oceans?
Exploration
PYTHEAS OF
MASSALIACIRCA 350285 BCEA Greek explorer who became
the first person to describe the
Midnight Sun in northern Europe.
5 ANCIENTMARINERS
NEARCHUSCIRCA 360300 BCENearchus provided details for the
book Indica, describing India after
Alexander the Greats conquest.
EUDOXUS OF CYZICUS130 BCEA Greek navigator, he is the first
recorded European to sail using
the monsoon winds in Asia.
HANNO THE NAVIGATOR500 BCEMost famous for his exploration of
the west African coast, he made it
farther south than anyone before.
FLOKI VILGERDARSONNINTH CENTURY CECredited with discovering
Iceland, he
used three ravens to help him find
land one of which led to Iceland.
TelescopeThe viewing poin
through which you aimat the horizon, before
moving the index bar
to align the Sun and
establish latitude
ArcThis is the measurement
readout, showing the angle of
the index mirror when the Sun
has been positioned correctly.
ShadesUsed to help stop glare
and make it possible
to position the Sun on
the horizon through
your telescope.
Index barUsed to move the mirror. The
gap is the viewing point fo
determining the Suns altitude
relative to your current position
ANATOMY OA SEXTAN
Index mirrorThe purpose of this is to capture
the Sun or pole star; the angle at
which it i s located wi ll then be
used to establish your position.
NAVIGATEWITHOUT A
COMPASS
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03Find the North StarThe most common point of reference in the
night sky
for sailors has always been the North Star (Polaris),
which sits directly above the Earths North Pole. Its
relatively
easy to find given that its one of the brightest stars in the
sky.
It can also be located by following down from the Big
Dipper(Ursa Major) constellation which sits above it.
North Star
The Big Dipper
05Sound out your depthAnother good reference for navigators is t
he oceans
depth, as this will give you a good idea of how far you
are from land. To establish how deep the water beneath you
is, you need to drop a sounding weight into the sea, with
its
attached rope serving as measurement. As well as depth,
these
devices can also collect samples from the ocean floor.
04Other constellationsThat is not to say the North Star is the
only celestial
body to guide you there are ma ny other stars that
move little and dont set that can serve as great guides when
youre out at sea. For example, take advantage of
constellations
Cassiopeia and the Big Dipper either side of the North Star to
more accurately gauge your heading.
North Star
(Ursa Minor)
(Ursa Major)
The Big Dipper
The Little Dipper
Cassiopeia
06Let birds lead the wayIf for some reason you lose sight of the
coastline
during the day and therefore have no stars to refer to
you can turn to the animal kingdom. A clever technique as a
final resort is to release birds that are kept on board and
then
follow them as they fly towards land. This is something the
Vikings did, using ravens to take them to new shores.
NAVIGATIONTOOLS
How not to navigateHaving found fame on his explorations in Asia
for the Egyptian ruler,
Ptolemy VIII, the Greek navigator Eudoxus of Cyzicus later
became intrigued
by the A frican coastline, when on the return journey of his
second voyage to
India, he was blown south of the Gulf of Aden.
On this detour he discovered the remains of a ship and, from
its
appearance and the details gathered from natives, Eudoxus
concluded it hadoriginated from Spain and had, albeit
unsuccessfully, circumnavigated Africa.
This inspired him to attempt rounding the continent himself.
Setting off
from the same point in Spain (Gades, which is modern-day Cdiz),
his first
attempt proved too difficult due to weather and distance, and he
was forced
to turn back. On his second attempt, Eudoxus vanished and his
fate has never
been discovered, though it is generally assumed he a nd his crew
foundered
during the attempt to complete the ambitious journey.
Exploration
USE THE MOON
N/AIf the Moon rises before theSun sets it is trailing the
Sun
and so the bright side will point
approximately west.
SUNSTONE13TH CENTURY CEUsed by Viking navigators on
cloudy days to determine the
location of the Sun thanks to th
way it polarised/refracted light.
JACOBS STAFF400 BCEThis device was used to measu
angles eg the angle between
the horizon and the Sun in ord
to establish a ships latitude.
THE ANTIKYTHERAMECHANISM1ST CENTURY BCEBuilt with up to 30
gears, this
ahead-of-its-time device worked
like a modern clock to predict t
location and alignment of stars.
