What Is A Nautical Chart? Everything You Need to Know

What is a nautical chart?

A nautical chart, also known as a maritime chart, is a specialised map used by mariners to navigate safely and accurately through waterways. These charts provide detailed information about the geography, depths, topography, and other navigational features of bodies of water such as oceans, seas, and rivers. They provide information on water depths, shoreline features, navigational aids, underwater obstructions, and other important information necessary for safe navigation.

Nautical charts are typically created by government agencies, such as the National Oceanic and Atmospheric Administration (NOAA) in the United States, and are updated regularly to reflect changes in water depths, navigational aids, and other features. They are essential tools for mariners and are used in conjunction with other navigational instruments and technologies, such as GPS, radar, and sonar, as well as electronic navigation apps like Savvy Navvy, to ensure safe navigation.

History of nautical charts

The history of nautical charts dates back to ancient times when sailors used simple maps and sketches to navigate the seas. However, the earliest known nautical charts that have survived to this day are from the medieval period.

During the 13th century, Genoese and Venetian mapmakers created charts for the Mediterranean Sea. These maps included information on coastal landmarks, ports, and navigational hazards. The charts were hand-drawn on parchment or vellum and were decorated with colourful illustrations.

In the 15th century, Portuguese navigators began to explore the coasts of Africa and the Atlantic Ocean, using charts that showed the prevailing winds and currents. These charts were essential for navigation in uncharted waters, and they helped the Portuguese sailors to discover new lands.

During the Age of Exploration in the 16th and 17th centuries, European explorers began to create more detailed and accurate nautical charts. The Dutch, in particular, were known for their skill in chart-making, and they produced some of the most detailed charts of their time.

In the 18th and 19th centuries, the British Admiralty became the leading producer of nautical charts. They created charts that covered all the oceans of the world, and these charts were used by sailors from many different countries.

With the advent of electronic navigation systems such as the Savvy Navvy boat app, the use of paper charts declined, but nautical charts remain an important tool for mariners. Today, modern nautical charts are produced using computer technology, satellite imagery, and other advanced techniques (such as smart algorithms for routing and multiple data sources for weather data), which have made them more accurate and detailed than ever before.

Having said this, it is still recommended that all boaters know how to use both paper and digital charts so they can cross-check their traditional and modern navigation plans for enhanced safety.

What sort of information do nautical charts provide?

Nautical charts provide a wealth of information for mariners to safely navigate the waterways. The information typically found on a nautical chart includes:

1. Water depths: The chart will show the depth of the water at various locations. This information is essential for navigating shallow waters and avoiding grounding. Within the Savvy Navvy app, you can tap anywhere on the Savvy charts™ to display the depth at that given location.
2. Hazards: Nautical charts indicate potential hazards to navigation such as rocks, reefs, shoals, wrecks, and obstructions.
3. Navigation aids: Charts show the location of navigation aids such as buoys, beacons, and lighthouses, which help mariners navigate safely through channels and shipping lanes. Within apps like Savvy Navvy you can also get further information such as the name, colours and light sequences of the buoys.
4. Bottom composition: The chart may indicate the type of bottom composition, such as sand, mud, or rock, which can affect anchor holding and vessel stability.
5. Tides and currents: The chart may provide information on the expected tides and currents in the area, which is important for safe navigation.
6. Shoreline features: charts show shoreline features such as beaches, cliffs, and promontories, which can help mariners identify their location.
7. Magnetic variation: you can view the angle between true north and magnetic north, which is important for accurate navigation with a compass.
8. Chart datum: The chart will indicate the vertical reference level used for the water depth measurements, which can affect the accuracy of the depth readings.

It is also handy to note that the Savvy Navvy provides all of these features in their boating app, available to download on the Apple or Google Play stores.

All of these pieces of information are essential for safe and efficient navigation, especially in unfamiliar or hazardous waters.

What are the main types of nautical charts?

There are several types of nautical charts used for navigation at sea. Some of the main types include:

1. Electronic Charts (ECDIS): These are digital charts that are used on electronic chart displays and information systems (ECDIS). They provide real-time information, including position, speed, and direction, and can be updated easily.
2. Paper Charts: These are traditional paper charts that have been used for centuries. They are still widely used by many mariners, especially as a backup to electronic charts.
3. Bathymetric Charts: These charts show the depth of water and contours of the ocean floor. They are used primarily by mariners navigating in shallow waters or near underwater obstructions.
4. Harbour Charts: These charts are used for navigating in ports and harbours. They show the location of docks, marinas, buoys, and other navigational aids.
5. Coastal Charts: These charts cover a larger area than harbour charts and are used for coastal navigation. They show landmarks, currents, tides, and other information useful for coastal navigation.
6. Pilot Charts: These charts provide long-term data on wind and weather patterns, currents, and other information useful for planning a voyage. They are particularly useful for long-range planning, such as ocean crossings.

Apps like Savvy Navvy combine many of the above-listed specific charts into one easy to use app so that you have all the essential information you need, in one place. 

Which nautical charts are better: paper or electronic?

Both paper and electronic nautical charts have their advantages and disadvantages, and the choice of which to use ultimately depends on personal preference and the specific needs of the user.

Paper charts are the traditional choice and are still widely used by many mariners today. Some advantages of paper charts include:

• Reliability: Paper charts are not dependent on batteries or electronic devices, and can be relied upon even if electronic systems fail.
• Familiarity: Many mariners prefer the tactile experience of using a paper chart, as they are often easier to read and understand than electronic charts.
• Historical value: Paper charts can be kept as historical records and are often treasured by mariners as a symbol of their experiences.

On the other hand, electronic charts have become increasingly popular in recent years, and offer several advantages over paper charts, including:

• Ease of use: Electronic charts can be easily updated and customised and can be zoomed in or out to show more or less detail as needed.
• Real-time information: Electronic charts can incorporate real-time information, such as weather data and AIS (Automatic Identification System) information, which can be extremely useful for navigation.
• Space-saving: Electronic charts take up much less space than paper charts, and can be stored on a variety of devices, including laptops, tablets, and smartphones.

In summary, both paper and electronic charts have their strengths and weaknesses. Ultimately, the decision of which to use will depend on personal preference and the specific needs of the mariner. Many mariners today choose to use a combination of both paper and electronic charts for added safety and convenience which is something we would recommend. 

The Summary

Here is a summarised overview of nautical charts that might come in handy:

1. Types of Nautical Charts: There are two types of nautical charts: Electronic Navigational Charts (ENCs) and Paper Nautical Charts. ENCs are digital charts that can be used with an electronic chart display and information system (ECDIS) or a chart plotter, while Paper Nautical Charts are traditional printed maps that have been used for centuries by mariners.
2. Components of a Nautical Chart: A nautical chart typically includes a variety of features and information such as depth soundings, navigational hazards, coastal landmarks, magnetic variations, ocean currents, tides and tidal currents, and other information that can help mariners navigate safely on the water.
3. Symbols and Abbreviations: Nautical charts use a variety of symbols and abbreviations to convey information. For example, buoys and beacons are marked with different shapes and colours to indicate their purpose and location. Navigational hazards such as rocks and wrecks are also marked with specific symbols.
4. Chart Datum: Chart datum refers to the reference level used to measure depths and other features on the chart. Different chart datums may be used for different charts, depending on the location and purpose of the chart.
5. Updating Nautical Charts: Nautical charts are constantly updated to ensure that they reflect the latest changes in the waterways. Changes can include new navigational aids, shifts in the location of channels and sandbars, and changes in water depth due to natural processes or human activities.
6. Importance of Nautical Charts: Nautical charts are essential for safe navigation on the water. They provide mariners with the information they need to navigate safely and avoid hazards. Without nautical charts, it would be much more difficult and dangerous to navigate on water.

In summary, nautical charts are specialised maps used by mariners to navigate safely on the water. They provide detailed information about the geography, depths, topography, and other navigational features of bodies of water, and digital and electronic charts are essential for safe navigation on the water.

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Looking for more information?

Here are some useful links!

• Nautical charts - an essential navigation tool for sailors and marine fishermen
• What are nautical charts used for?
• What is a nautical chart?

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