Understanding Nautical Chart Symbols in the Age of Digital Navigation
Learning how to use a boat also means learning how to read and use nautical charts. Today, apps like Savvy Navvy provide digital solutions to instantly check your position, review electronic chart data, weather forecasts, and even plot routes. However, it is still important to fully understand charts and be confident reading them so that you can cross-check your digital and traditional navigation plans.
Why nautical chart symbols matter
Nautical charts contain a wealth of information, including charted depths, hazards, recommended tracks, Traffic Separation Schemes, key landmarks, and navigational aid symbols. Understanding these symbols is crucial for safe navigation. While digital tools enhance accessibility, foundational knowledge remains essential.
Common nautical chart symbols and what they mean
- Depths: Shown by contour lines and numbers indicating depth in feet or fathoms. Look for colour coding: blue for deep water, green and brown for shallower depths.
- Navigational aids: Markers such as lighthouses (tower symbols) and buoys (shapes and colours indicating type and location). Digital tools may display additional details like light sequences and fog sound sequences.
- Obstructions: Hazards such as rocks, shoals, wrecks, and underwater dangers, often shown in black or red.
- Anchorages: Indicated by an anchor symbol, often with depth information.
- Channels: Marked routes indicating width, direction, and hazards.
- Landmarks: Buildings, towers, or churches, shown by unique symbols.
- Fishing areas: Indicated by specific symbols highlighting permitted fishing zones.
- Military zones: Areas marked for military activity with unique symbols.
How to read nautical chart symbols
- Understand colour coding: Blue for deep water, green/yellow/brown for shallower areas.
- Identify navigational hazards: Rocks, wrecks and obstructions are highlighted in black or red.
- Look for additional information: Such as tides, currents, and navigation aids (shown in the layers options within Savvy Navvy)
- Consult the legend: On paper charts you can check the chart key for symbol meanings, on digital charts you can tap the icon for more information.
- Zoom in for more detail: Apps like Savvy Navvy allow zooming and interactive exploration allowing you to take a closer look at charted symbols and the area around them.
Navigational symbols and abbreviations
Some common marine navigation abbreviations:
- Lat: Latitude
- Long: Longitude
- CHTS: Charts
- DR: Dead Reckoning
- Hdg: Heading
- Fathoms: Depth measurement
- M: Magnetic
- True: True direction
- ANCH: Anchorage
- ATON: Aids to Navigation
- Brg: Bearing
- CH: Church
- CRAN: Crane
- DNG: Danger
- FISH: Fishing
- HW: High water
- LW: Low water
- RACON: Radar Beacon
- SHL: Shoal
- SNDG: Sounding
- SP: Signal Post
- WDSP: Windsock
Safety symbols overview
Nautical safety symbols are graphical representations used on marine charts, maps, and publications to convey information about hazards, navigational aids, and other important information related to maritime safety. Some common nautical safety symbols include:
- Anchorage symbol: A circle with an anchor inside indicates the location of a safe anchorage.
- Buoy symbol: indicates the location of a floating device used as a navigational aid or to mark hazards.
- Rocks or shoals symbol: A symbol that looks like a group of rocks or a triangle with a dot in the centre is used to indicate the location of rocks or shoals that pose a hazard to vessels.
- Wreck symbol: A symbol that looks like a sunken ship or a crossed-out anchor indicates the location of a sunken vessel.
- Safe water mark symbol: A symbol that looks like a diamond with horizontal stripes indicates the location of safe water, which is free from obstructions and navigational hazards.
- Restricted water symbol: A symbol that looks like a diamond with vertical stripes indicates the location of restricted water.
- Depth contour symbol: A symbol that looks like a series of concentric circles indicates the depth of the water in a particular area.
- Landmark symbol: A symbol that looks like a small building or tower indicates the location of a prominent landmark that can be used for navigation.
- Compass rose symbol: A symbol that looks like a star with directional arrows that indicates the orientation of the chart and the direction of true north.
These are just a few examples of the many nautical safety symbols used in marine navigation. It's important for mariners to be familiar with these symbols and to use them to safely navigate through coastal waters and inland waterways.
Using nautical charts: best practices
- Understand the symbols: Make sure you understand what each chart symbol means before setting out on your journey.
- Use a compass rose: Nautical charts include a compass rose that is used to show the orientation of the cardinal directions.
- Calculate distances: charts provide distance scales that can help you calculate distances between two points. However, keep in mind that these distances are measured in nautical miles, which are slightly longer than regular miles.
- Take note of tide and current information: charts often provide information about tides and currents, which can be very useful for planning your route and avoiding dangerous conditions.
- Check for updates: ensure your charts are updated regularly to reflect changes in the environment, such as changes in water depth or the location of navigational aids. Be sure to check for updates before setting out on your journey to ensure you have the most current information. Electronic charts, such as Savvy Navvy charts, often do this automatically.
- Use a digital navigation aids: Many modern boats are equipped with chart plotters, which use GPS technology to display your boat's location on a nautical chart in real-time. Most boaters also use navigation apps like Savvy Navvy to view their live GPS location. This can be very helpful for navigating unfamiliar waters.
- Practice safe navigation techniques: Always use a combination of tools and techniques to navigate safely, including nautical charts, GPS, and visual observations. Never rely solely on one method of navigation.
Nautical chart symbol differences across charts
Different charts, whether paper or electronic may use variations in colours and symbols. Always check the specific chart's legend or instructions to be sure you're using them correctly. Examples:
- Depths: Different colours or contour styles.
- Rocks/reefs: Star or dot symbols.
- Lighthouses: Solid or broken-line triangles.
- Buoys: Varied shapes and colours.
The rise of digital navigation
The rise of digital navigation tools like Savvy Navvy has made it much easier for recreational and professional boaters alike to view, interpret, and use nautical chart symbols. Digital charts allow zooming, interactive layering (wind, tides, AIS, etc.), and tapping on symbols to reveal additional information such as buoy names, sounds and light sequences.
Enhanced learning and training
Industry bodies like the UKHO and RYA are championing digital-first navigation education. Training blends paper-chart fundamentals with real-time app use.
Sarah Quinn from Dorset Marine, a specialist in powerboat training, says:
"We show students a paper chart to explain the basics of navigation and plan their passage and pilotage, we then switch to digital. A paper chart on a RIB or day cruiser is not always practical. We find our students enjoy using Savvy Navvy in the way it brings tides, weather, chart-data and planning into one tool. It’s not just what they need; it’s what they expect. We wouldn’t leave without a paper plan, but digital navigation is at the forefront of people’s minds."
Takeaway for boaters
Understanding chart symbols remains essential. With the help of digital navigation, accessing, interpreting, and applying that knowledge has never been easier or faster. Combining both traditional skills and digital tools ensures safe, confident navigation when out on the water.
To get started, download the Savvy Navvy app for a safer, easier way to navigate at sea.
