Chart Work & Equipment

Navigation Equipment and Chart Work

Protractors & Parallel Rulers

We recommend using a Chart Protractor (e.g. Bi-Rola) as opposed to (or in addition to) parallel rules. You can place this protractor anywhere on the chart and rotate the protractor to line up to your grid lines. You can then read off the bearing that the ruler is lying on.

e 40 Navigation/Chart Work Rulers
Chart Work Rulers


The top ruler is the Chart Protractor. Parallel rules are a good tool, but when ‘walking’ them across a chart it is easy to slip and slide, especially on a moving boat.


Image 41a Navigation Dividers
Image 41a Navigation Dividers
Image 41b Navigation Dividers
Image 41b Navigation Dividers

Dividers are excellent for measuring distances accurately, of course, you can use a simple pencil compass to do the same job. However, for larger distances the dividers (picture above) open out wider enabling the navigator to measure longer distances with less error (usually caused by stepping or walking the dividers along a line).

Image 42 Pencil Compass
Image 42 Pencil Compass


Pencil compass

A pencil compass is necessary for drawing arcs during navigation.

Equipment List

2B pencils

Soft eraser

Onboard, in addition to the above, you will need:

Compass to take bearings

Accurate clock

Sounding device

Calculator (double check your calculations)

TIP: Electronic equipment is an ‘aid to navigation’ and requires back up as per the equipment listed above, plus your knowledge on how to use the equipment correctly and navigate. The skipper is responsible for everything and everyone on board.

Position: Correct Chart Work & Symbols

On the chart, use the following symbols so everyone understands the workings.

Image 43 Marine Navigation Chart Symbols
Image 43 Marine Navigation Chart Symbols