The China Sea directory - Sabrizain.org

INFORMATION RELATING TO CHARTS, ^AlLIN0
DIRECTIONS, AND THE GENERAL NAVIGA-
TION OF H.M. SHIPS.
ON THE CORRECTION OP CHARTS, LIGHT LISTS,
AND SAILING DIRECTIONS.
There are three descriptions of publications as guides to naviga-
tion—the charts, the sailing directions, and the light lists—which
are all affected by the continual changes and alterations that take
place.
Of these the charts should always be, so far as our knowledge
permits, absolutely correct to date ; and the light lists should be
noted for the recent alterations, though space will not permit of full
details being always inserted ; the sailing directions, however, cannot,
from their nature, be so corrected, and in all cases where they differ
from charts, the charts inust be taken as the guide.
Charts.—^When issued to a ship on commissioning, the charts have
received all necessary corrections to date. As sent from the
Hydrographic Office they are, as a rule, fresh from the plates.
They then receive such corrections by hand in the depdts as are
required, and are so issued to the ships.
All small but important corrections that can be iilade by hand are
notified by Notices to Mariners, and should at onde be placed on the
charts to which they refer.
Large corrections that cannot be conveniently thus made are put
upon the plates, and fresh copies are issued to the ships to replace
the others, which are directed to be destroyed to prevent the
possibility of their being used in the navigation of the ship.
The dates on which these large corrections are made are noted on
the chart plates in the middle of the lower edge ; those of the
smaller corrections at the left-hand lower comers.
In all cases of quotations of charts, these dates of corrections
should be givJh, as well as the number of the chart, in order that