Different Types of Nautical Navigational Charts for Sailors

For centuries, nautical charts have been used as important tools for sailors, securing safe navigation across oceans, seas, lakes, and rivers.

There are many types of navigational charts available, which can make it difficult to choose the right option for your particular needs. In this article, we explore the different kinds of navigational charts and their purpose.

What Are Navigation Charts?

Navigational charts are carefully produced by the relevant hydrographic offices worldwide to provide a detailed picture of what lies beneath the water. This includes water depths and potential obstructions such as reefs, shoals, and wrecks.

Here in Australia, the Australian Navy and UK Hydrographic Charts are the official charts to carry and use, and both of them are available at Boat Books.

They detail features ranging from beaches to cliffs, as well as structures like lighthouses, buoys, and beacons for safe navigation. They also outline the range in size and scale, but typically focus on a specific strip of coastline.

In modern times, seafarers can choose between digital maps and paper charts, but most experts recommend using a combination of both.

Different Types of Nautical Charts

When at sea, sailors use several different scales of navigational charts to plan the safest routes and find the best course of travel. Each chart is detailed, guiding the sailor through the waters and allowing them to plan for any potential hazards and estimate the amount of time they will spend at sea.

Nautical charts, which can now be accessed digitally, have become significantly more accurate thanks to advancements in satellite technology. Let’s take a look at a few different kinds of navigational charts and their purpose.

Electronic navigational charts are digital charts used in conjunction with electronic navigation systems.
Raster navigational charts are digital versions of paper charts designed for online systems.
Paper charts are traditional navigation charts used as backups or in areas where there is no electronic coverage.
Planning charts are large maps designed for trip planning rather than navigation.
Tidal charts display tides and currents, allowing you to plan your trip accordingly.
Ice charts show the current ice conditions in areas with ice to help you avoid hazards.
Coastal charts are detailed maps of coastlines used for safe navigation.
Harbour charts are maps of ports and harbours that show docks and facilities.

What Are the 4 Classifications of Charts by Scale?

One of the main ways charts differ is by scale. The four main classifications include:

General charts: Provide a broad overview of an area, and typically offer scales of up to 1:150,000.
Coastal charts: Perfect for assessing specific strips of coastline, with scales ranging from 1:50,000 to 1:150,000.
Approach charts: These are used when approaching a busy traffic area, such as a port or bay. Scales usually range between 1:20,000 and 1:50,000.
Harbour charts: Generally, the most detailed option available, harbour charts have scales usually larger than 1:20,000.

The Evolution of Nautical Charts

From old stone tablets to digital formats, nautical charts have transformed drastically over the years. The earliest maps were based on careful observations made by sailors out at sea, but medieval portolan charts revolutionised navigation in the 13th century by detailing the Mediterranean and Black Sea coastlines.

Further findings were made during the Age of Exploration, and today’s GPS and electronic navigational charts offer accuracy for safer navigation and exploration.

How to Choose the Right Chart for Your Needs

With so many different kinds of charts available, you should take the time to assess which one will be right for your needs. Here are a few things to consider:

How much detail you need for your trip
The nature of your voyage and the type of vessel
Whether paper or digital charts would work best for you

Where Will You Find a Comprehensive List of Navigational Charts?

The official lists of navigational charts will differ from region to region. Here in Australia, the best source is the Australian Hydrographic Office. The National Oceanic and Atmospheric Administration is best for US-based charts.

Here at Boat Books, we’re Australia’s largest marine chart agent, committed to inspiring commercial and recreational sea exploration. Check out our bookshop to learn more about how mariners strategically leverage different types of navigational charts for safe exploration.