The China Sea directory - Sabrizain.org

154 WEST COAST OF SUMATRA. [chap. in.
TIDES.—The rise of tide does not exceed 3 feet at springs, and in
places not far from the equator it is high water full and change at ahout
6 hours. On most parts of the coast there is generally a considerable
surf, which is highest in the southerly monsoon, during spring tides.
ROUTES. — The channels, or routes, along the Vest coast of
Sumatra may be considered as three in number :— (I) That to the westward
of all the islands, in the open sea, and named the Outer route ; (2) the
space between the chain of large islands, in the o£5ng, and those small
islands adjacent to and interspersed along the coast, which may be called
the Middle route, and ranges from 10 to 30 miles distant from the
shore of Sumatra ; (3) the Inner route, lying close along the coast and
between some of the islands near ; it is connected with the Middle route
in some places.*
Outer Houte, to the westward of all the islands, in the open
sea, is the best of the three ; for there, S.W. and southerly winds often
prevail, when N.W. squalls and variable baffling winds may be experienced
close to the land. A quicker voyage to the northward will thus be made
during either monsoon.
Middle Route.—The middle route should not be followed when
bound to the northward, nor at any time, if it can be avoided without
inconvenience; for although it is wide, and may be adopted by night
or day, when the weather is clear and favourable, vessels are liable to be
drifted by currents when the winds are light and baffling, there being
no anchorage ; and in some parts towards the main, dangerous coral shoals
are situated near the edge of soundings.
Inner Route.—The inner route has been generally recommended
to navigators, but it probably is meant to apply to vessels trading between
the different places on the coast, and it should seldom be chosen by
vessels bound to the northward in either monsoon ; but as there are in
many places moderate depths for anchoring, it is preferable in that respect
to the Middle route. On account, however, of the numerous small
islands and many dangerous shoals, the true positions of which are
not correctly determined, it is, to persons unacquainted, an intricate and
embarrassing passage. Vessels proceeding by it"are generally obliged to
anchor during the night.
Coral reefs.—It has been said, that all the shoals on this coast are
white coral rocks, discernible from the masthead about one mile off in the
daytime, even when they are 3 fathoms under water. On the contrary,
many of the shoals consist of black rock, not discernible until close to them,
although covered only with 8 or 10 feet water ; and several vessels have
grounded upon these shoals in the daytime before they could be perceived,
* Horpburgh.