This text focuses on electronic navigation applications for small craft. These electronic applications are used to display electronic charts. For concrete examples, this site includes five introductions to different applications: Navionics (Boating), OpenCPN, C-MAP, Savvy Navvy and SEAiq. Below, I detail the elements common to navigation applications generally found on small craft such as sailboats, yachts and the like.
1. Apps automate certain navigation tasks
The main advantage of an electronic application is that it automates certain navigation tasks. They can automatically determine the boat’s position and speed; they can build, save and share routes; they can record the actual path taken by the boat; and they even offer assistance with passage planning. In particular, some applications display tide cycles directly. If the application is reliable, it is no longer necessary to calculate tide windows by hand.
Automating these tasks saves time. Less time is spent determining where the boat was. In turn, more time can be spent anticipating where the boat will be, improving navigation safety.
2. You need a computer to do it
Some form of computer is needed to run navigation applications. Sometimes it’s a chartplotter. Popular brands are Raymarine, Garmin or Simrad, but there are others.
However, these computers are relatively expensive ($2,000 or more), and it’s also an established practice to use a cell phone or tablet computer (e.g. iPad, etc.). These devices are not all equal in terms of use and possibilities. The capacity of the battery will affect the duration of passages. Also, screen size will be a factor affecting how easy it is to plan routes: the larger the screen, the better it is for planning… but the more power it will consume. To mention two extremes, the Garmin inReach GPSMAP has a screen measuring about one inch by one two inches. It’s tiny, but its battery life is several days. Conversely, a Samsung tablet will have a screen of around 11 inches by 7 inches. It’s bigger, but with a display setting for the sun, its battery will only last a few hours.
For diy-ers, it’s also possible to use a microcomputer such as a Raspberry pi (and this isn’t something I’ve tested). The advantage is that it’s not expensive.
3. Mapping information comes from the government
Whatever your favorite application, if you’re displaying a map on Canadian territory, the data transmitted by most electronic applications comes from the Canadian Hydrographic Service. Private companies operating these applications pay user fees in exchange for access to government map data.
In this sense, no matter which application provider you choose, you’ll get essentially the same cartographic information. There may be differences in color or certain symbols, but the maps will display the same depths, buoys, etc. The only differences are in the way they are displayed. The only differences are in update mode and graphical appearance.
To use an analogy, you might prefer Coke to Pepsi, but it’s all the same: water, sugar and carbon dioxide. The differences are just a few ingredients!
I take the trouble to write “most” applications rather than all, as some may rely on third-party services. If this is the case, you should exercise great caution and assess the quality of the data obtained. It’s possible that the data on the maps is out-of-date, wrong, or both!
4. Map symbols vary from one application to another
The International Hydrographic Organization maintains a standard for symbols on navigational charts. Adhering countries ensure that their charts are as close to the standard as possible. This ensures that paper charts look the same no matter what part of the world they cover (and where they come from).
Where there are differences, these standards are recorded in a document calledChart#1. This document is produced by any hydrographic service that produces charts. Below, I show an extract from Chart #1 of the Canadian Hydrographic Service, but it’s also possible to download the same document for France, the UK, the USA or others.
Many electronic navigation applications use symbols that differ from the international standard. Some applications even offer the option of configuring the display standards to suit personal taste. These differences are generally minor, but can sometimes lead to confusion. If you’re just starting to navigate with a new electronic application, it’s a good idea to familiarize yourself with the tool it uses to read the symbols on the map. In this respect, applications differ greatly: some don’t display all symbol-related information, while others offer a wealth of detail. The most important differences concern bathymetry, water depth and “natural” navigation hazards (rocks in the water, etc.).
5. The device must be equipped with or connected to a GPS
Finally, the device must be connected to a GPS, or have a built-in GPS. Otherwise, it will be impossible to know your boat’s speed and position! Similarly, it won’t be possible to record the actual course your boat has taken. As a result, your electronic navigation application is reduced to a map display.
It’s worth noting that iPads only have built-in GPS on models that include a cellular chip. If you want to dedicate a tablet to a navigation application, you’ll need to check that a GPS is included with the tablet.
Laptop computers (Mac or PC) allow you to use certain navigation applications (e.g. OpenCPN, SEAiq). As a general rule, these computers do not come with a built-in GPS. One practice is to purchase an external GPS that can be connected via a USB port, and then ensure that the application can “see” the GPS. This approach requires configuring the application, the computer or both! Another approach is to connect your computer to your sailboat’s NMEA network, if you have one, and be prepared to do a bit of tinkering.
6. The application displays the position of the GPS receiver
Your application will display the data received by your GPS receiver. If this receiver is installed on your sailboat, it will intrinsically display the boat’s position and speed. On the other hand, if you’re using a cell phone or mobile tablet with built-in GPS, the application will display the position and speed … of your device. The difference is significant if you’re walking on your boat (or on the dock) while reading the speed and position information. If you’re walking in the direction of the boat, your displayed speed will be greater than if you’re standing still on the boat.
Similarly, the actual route taken that is recorded is that of the device… and not of the sailboat. The image on the left, a screenshot of the route recorded with C-MAP, clearly illustrates the difference between the two.
The erratic behavior in the middle of the image has nothing to do with the skills of the person at the helm! On the contrary, the zig-zags show the combined effect of the boat and the cell phone recording the course. This phone was in my pocket while I was going back and forth on deck.
In short, the device measures the position of the GPS receiver. If this receiver moves in relation to the boat, the information will be slightly distorted.
7. No need for cellular data
Most navigation applications do not require cellular data to navigate. You do, however, need to download navigation maps in advance, which you can do with a wi-fi connection or a data plan.
Some applications offer map subscriptions that are less expensive, but do not allow you to download the maps. In other words, this type of subscription requires a cellular connection. Needless to say, it’s not good practice to use these subscriptions for navigation more than five nautical miles offshore. After that, cellular reception is lost.
In an emergency, any device with a GPS receiver will display GPS coordinates without a cellular connection… and without an electronic navigation application. All you need to do is download an application that displays longitude and latitude coordinates. Of course, you’ll need to know how to transfer this information to a paper map.
8. It’s wise to have redundancy
When it comes to portable electronic devices, it’s possible to lose them, drop them in water, run out of batteries or break them. I’ve sometimes dropped a device in the water, or been unable to charge it because it was too exposed to the rain.
In fact, it’s a safe practice to have a second device with an application installed, up to date, and with charged batteries. Similarly, it’s good practice to bring more than one charging cable, and an external battery to recharge it.
9. It’s wise to bring your own camera
If you’re sailing on someone else’s boat, the capabilities and status of the onboard system’s electronic cards will be unknown until you’re on board. Electronic devices are subject to repairs and electrical tinkering by others. It’s not impossible to experience broken screens, blown breakers or out-of-date maps. If navigation depends on someone else’s electronic device, it’s a good idea to bring your own.
10. Legally, you still need paper maps
The USA, France, the UK, New Zealand and Australia recognize electronic applications as acceptable substitutes for paper maps. In fact, neighboring countries (notably in the Caribbean) are following the lead of the major maritime powers. In Canada, however, this is not the case for recreational boaters.
For pleasure craft, the Navigation Safety Regulations specify that paper charts of an appropriate scale must be carried on board, unless you are familiar with the body of water on which you are sailing. It’s important to understand that if you’re sailing repeatedly in known waters, you don’t need charts. But if you’re traveling in new waters, Canadian pleasure craft must have paper charts.
I’m one of those who believes that this regulatory obligation should change, in particular to keep pace with the practice of the vast majority of boaters, and to allow electronic applications. However, this is not yet the case, and if we want to comply with the law, we need paper on board (and more generally, nautical publications). To follow the evolution of e-navigation in Canada, visit the Canadian Coast Guard’s e-navigation portal. In particular, the page detailing the government’s roadmap clearly illustrates the challenges involved in the transition to electronic navigation.
11. You’ll only see the route and speed on the background
Unless your navigation app is connected to a compass attached to your sailboat and log, you’ll only see your course over ground (COG) and speed over ground (SOG). Succinctly, this information indicates in which direction the boat is heading (as opposed to where it’s pointing) and how fast the boat is going in relation to the ground. If you’re unfamiliar with these concepts, I encourage you to take a navigation course.
With a tablet or cellular device, it’s impossible to know your speed on the water, or your drift caused by the current. To estimate this information, you have to do it by hand, or connect your app to the sailboat’s instruments.
12. Two pricing models
Electronic navigation applications essentially provide two services: 1) displaying navigation charts; and 2) providing user-friendly software with additional functions. From the user’s point of view, these two things are almost the same: using the application necessarily implies displaying maps. However, from a production point of view, these services are completely different: the software is produced by a private company, but the charts are produced by the Canadian Hydrographic Service (or another hydrographic service elsewhere in the world).
Some hydrographic services, such as the National Oceanic and Atmospheric Administration (NOAA, in the USA) or the New Zealand Hydrographic Service, make their charts available to the public free of charge. In most other countries, notably Canada, hydrographic services sell their products to resellers or suppliers under service contracts. This includes companies producing electronic navigation applications.
Because of this difference in production source, companies opt for different pricing models.
Monthly subscription
The first model – the most common – consists of an application that can be downloaded free of charge, but requires an annual subscription to use a group of maps. With a single fee, the application covers not only its contractual costs to the Hydrographic Service, but also the application’s development and maintenance costs.
Purchase of software and maps
The second model separates software production costs from map usage costs. In this case, you pay for the use of the software, and pay an additional amount if the hydrographic department asks you to pay for their services.
This pricing model is clearer, because it shows that if the charts are available free of charge, as in the USA, the only costs are for the software. An annual subscription, on the other hand, conceals the fact that some charts are free for the software developer.
Conclusion
Electronic navigation applications are great tools for automating certain navigation tasks. They do not, however, dispense with the navigator’s obligation to perform these tasks manually, or to plan his routes. Understanding their use and limitations also helps to make them your own. This text, covering a number of general points, covers a wide range of applications often available on small boats or pleasure craft.
For the specifics of each application, please refer to the Learning section of this site. It includes texts on the Navionics (Boating), OpenCPN, C-MAP, Savvy Navvy and SEAiq applications. In particular, it covers how to perform eight essential navigation tasks:
- obtain charts;
- read symbols on a map;
- plan a route;
- save the actual route taken;
- obtain speed and course over ground;
- obtain current and tide information;
- exchange previously created routes;
- plan and execute routes.
They are more practical to read, and more focused on the use of each application.
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[…] Prior to reading this text, it is a good idea to reat the introduction to electronic charts and the introduction to electronic navigation applications. Both will help understand this […]