Yachting

PRACTICAL SEAMANSHIP

PHOTO: GRAHAM SNOOK/YM
Update electronic charts via download, CD,
or getting a new chip from your provider

Imray, Laurie, Norie and Wilson was formed in 1904 in London, when

three private chart companies, each dating back to the mid 1800s,

amalgamated. Lucy works with sister Pip, Ian Rippington (of the Imray

family) and her father Willie Wilson. Imray’s range of yachting charts

and books is still the most comprehensive available.

Whenever you update a chart,

note the NM used. That way

you know the chart is

absolutely contemporary

The key is accuracy and clarity:

the chart must be up to date and

easily readable in sometimes

diffi cult conditions onboard

Clear corrections

The main consideration is

clarity. Avoid clutter. Words

and symbols should be

kept as small and precise

as possible. Existing marks

or contours that need to

be overwritten should be

crossed out clearly (in the

case of text or symbol) or

with several small dashes

perpendicular to a contour

line. If you need to use

an arrow to point to a

particularly small point of

correction, it’s best that the line

of the arrow crosses any existing

contours at right angles to avoid

it becoming muddled with the

line of the contour. It’s usually

tidier to correct only the part of

a light characteristic that needs

changing rather than changing

the entire characteristic.

36 http://www.yachtingmonthly.com MAY 2016

Electronic charts also need updating. For

those, it’s usually a case of downloading

updates, sending off to the publisher for a

It’s important to update your chart chips, too

PHOTO: GRAHAM SNOOK/YM
Update electronic charts via download, CD,
or getting a new chip from your provider

36 http://www.yachtingmonthly.com MAY 2016

Electronic charts also need updating. For

those, it’s usually a case of downloading

updates, sending off to the publisher for a

It’s important to update your chart chips, too

Update electronic charts via download, CD,

or getting a new chip from your provider

Electronic charts also need updating. For

those, it’s usually a case of downloading

updates, sending off to the publisher for a

It’s important to update your chart chips, too

It’s counterproductive to

scrawl a new set of light

characteristics in thick black

pen, obscuring the detail

underneath. The aim is to

make neat, tidy and long-

lasting corrections that can

be read in bad conditions.

Use a 2B pencil for tricky

corrections such as linework

before going over in pen.

Rub out any mistakes or old

pencil corrections with a soft

rubber such as a Staedtler

Mars Plastic Eraser, which

won’t mark the chart itself.

At Imray, we correct

using a Uni Ball Signo

UM-151 in either 2.3 or 5mm

depending on the size of

correction. It’s a fi ne-tipped

pen with non-bleeding ink

that is semi-permanent even

on the waterproof Pretex

paper used for Imray charts.

The Admiralty

recommends that

corrections be made in violet

ink so that they are clearly

visible. For tracings, a 7H

pencil is recommended.

A ruler is also useful so

that you can accurately

check the latitude and

longitude position of the

correction that you want to

make, using the graticule

(the network of lines on the

chart representing meridians

and parallels) as a guide.

For block corrections, use

a Stanley knife and ruler to

cut the correction from the

page as close to the edge as

possible, leaving no black

line or white border. Find

the position on the chart

(sometimes the lat and long

reference is given) and stick it

on using a spray glue such as

3M Spray Mount so that you

can reposition it if necessary.

For drawing sectors or large

circles, you’ll need a pair of

compasses.

Another tool that’s worth

having, if you are a serial chart

corrector, is a hacksaw blade.

A 14 teeth-per-inch blade is

ideal for drawing submarine

cables – just put the toothed

edge where the cable should

go and run your fi ne-tipped

pen along it.

The right tools

Tools of the

trade: none is

expensive, and

they’ll earn their keep

The key is accuracy and clarity:

A hacksaw blade is perfect for

adding submarine cables

Keep a record

of your updates

It’s good practice to make a note

of the NM or correction notice

number on the chart itself. That

way you know how up to date

the chart is. Admiralty charts

have a small box on the back in

which you can mark the date

of the latest correction and the

notice to which it refers. Imray

charts have space next to the

printed date at the bottom

left where you can mark the

reference number of the notice

to which it is corrected. W

PRACTICAL SEAMANSHIP

code, CD or DVD, or taking the chart chip

back to your provider. Updates are often a

bit cheaper than a brand new chart. There’s

more detail on updating electronic Admiralty

publications in the publication NP294. Check

for the latest updates before you sail.