PRACTICAL SEAMANSHIPPRACTICAL SEAMANSHIP
PHOTOS: NICK RIDLEY UNLESS OTHERWISE STATED
Block corrections must be
printed to scale, carefully cut
out and then accurately appliedBlock corrections
These are for changes to contours
or lines on the chart that would
be diffi cult to explain in text, or
a table with details of depths or
tides. You simply cut them out
and stick them onto the chart.
You can download these from
the relevant website, or ask the
Admiralty to send them to you,
via ‘Notices to Mariners’ on the
website. Take care to print them
at ‘actual size’, and use good
quality colour ink on a laser or
inkjet printer with a resolution of
300dpi or greater to ensure
that they’re good and clear.Text corrections need to be made in such a way that the rest of the
chart’s data is not obscured. Use a fi ne-tipped pen and a steady handFor centuries, the paper chart has been the rock on which safe navigation is built. It’s vital that you keep yours accurate and updatedText corrections
These explain changes to symbols
or text on the chart. Changes to
light characteristics are probably
most common. You can easily
make these changes by checking
the latitude and longitude
position on the chart and copying
the correction from the notice.
Some relevant chart symbols
are listed on the NM, for others
you may need to refer to the
Admiralty’s fully comprehensive
NP5011 List of Symbols. The Imray
website includes a key to oursymbols and this is also printed
on the back of the charts.
The Admiralty also issues
corrections printed onto tracing
paper, available to order at a cost
on its website. Tracings save time
in that you don’t need to search
for the correction using latitude
and longitude, you simply overlay
the tracing onto the chart and
trace the correction detail onto it.
The NM or correction notice
will usually tell you when to draw
in a new symbol and when the
correction should be text.MAY 2016 http://www.yachtingmonthly.com 35These are for changes to contours