Buy boat electronics or build your own? Our experience with autopilot, navigation and more

To make sailing comfortable and safe, many people like to have technology on board. Of course, there are also traditional sailors who stick their wet fingers in the air to determine the direction of the wind and see technology as a distraction. So they prefer to use as little as possible.

However, most boats in a given class will have at least a power supply, navigation lights, depth sounder, plotter, GPS or compass on board for navigation. There will also probably be some lighting that you can switch on and off with a switch panel or a barometer to monitor changes in the weather.

But what if you want to extend this with more technology, for example an autopilot or AIS. Or perhaps you would like to be able to remotely monitor your power supply and other sensors.
And what if something breaks down or is outdated? And you need to replace several pieces of equipment? There is always something to repair, replace or upgrade on your boat.

Often you have to go to what we call the maritime jeweler to buy equipment or parts at great expense. And, if you have it installed, there are of course additional installation costs. What’s more, you are often tied to one brand, as not all brands can communicate with each other.

Not everyone has the financial means to pay for new equipment. There are more and more people who, because of this fact or a healthy technological curiosity, consider making a self-built solution. With the idea of saving costs and expanding functionality.

This blog is meant to put the pros and cons of DIY solutions together and give an insight into the opinions we hear on the subject. Don’t get us wrong, there are many advantages as we too have embarked on this journey! But, if you are starting out or even if you are already familiar with it, we hope this article will help you.

There are several projects on Github, a website popular among hobbyists and developers with public code, and on other sources that have been made public. Based on this, you can easily find instructions to build your own plotter with GPS and watermaps, an autopilot or AIS receiver. If you want to go a step further, you can also build digital switching or even a multiplexer.

The possibilities are endless, but not everyone finds it as easy. However, many people without any IT knowledge and by following a manual can succeed in this. Anyone who dares to do so can, in any case, immerse themselves in these projects, then order parts online somewhere and start building.

Most plotter projects almost always start with a Raspberry Pi. These are small computers about the size of a credit card so they don’t take up a lot of valuable space on your boat. Next, you install a special operating system on it, in this example we take Openplotter.

Openplotter can be seen as a Linux operating system, but modified to include the software needed to run a maritime operating system. Openplotter is packed with APPS that give you lots of functionality, but before you can use all that functionality, you need hardware, lots of hardware.

Along with Openplotter comes the standard SignalK. Unlike the big maritime brands, SignalK is an open maritime data standard, and offers a possibility to share information via WiFi, smartphones, tablets and via the internet.
Together they offer a very nice software platform to build a complete maritime system, which goes far beyond just a plotter.

To use the system, you can connect a monitor or touchscreen to the Pi. Or you use your own smartphone, tablet or laptop to remotely control the computer or read the data. You can think of it as your home computer, only smaller and lighter. And not with Windows or MacOs, but with an adapted and extensive Linux system.

Do you want a simple plotter? Then before you can go out on the water with it, there are some parts and steps needed besides the Pi. You need sea charts, a program that can display them on your screen, your position and heading, but also a power supply to connect the Pi to your on-board battery or service battery.

If you have installed the fundamentals, then OpenCPN is available by default as a map plotter. This is the navigation software that can display the maps, but also other information that is relevant during navigation. If you have a monitor connected then you can use it directly. For your phone or laptop you can use a separate program “VNC” to remotely take over the desktop environment of the Pi and so see on your own device what you normally see on the screen.

OpenCPN itself has the possibility to download nautical charts, these are usually .KAP files derived from OpenSeaMap. OpenCPN offers on their website a number of links to free official map sources for many areas worldwide. Another useful feature is the download layer of OpenSeaMap, here you simply select a layer and download what you need. There are also several plug-ins available to support other map types. OpenCPN is packed with features, but it may take some time to configure and understand how everything works.

Then there is another chartplotter option we would like to mention. Within SignalK there is an app available called Freeboard. This is a web app which you can easily open using a web browser. Freeboard does not require you to download any maps, these are retrieved live over the internet in the form of .mbtiles.

If you do not have an internet connection, you can add an extra map source via an extra plug-in in which you can display your own downloaded .mbtiles. But, you can also add a satellite overlay from Google Maps, Bing or Esri. Freeboard has less functionality than OpenCPN, but is probably more smartphone or tablet friendly.

OpenCPN is perhaps more suitable for use with a keyboard or mouse. Within OpenCPN there is an option to indicate that you are using a touch screen, which makes operation a little easier. With a touchscreen we mean a physical touchscreen directly connected to the raspberry pi. Of course your smartphone and tablet also have a touchscreen, but to control OpenCPN with it you have to simulate mouse movements, left and right mouse buttons via VNC remote desktop.

The screens of your smart devices are often a bit smaller, so our experience is that you have to do a lot of zooming in and out to click exactly where you want to. For example, if you want to activate a route, you have to hover the mouse exactly on the line of the route, simulate the right mouse button with two fingers, then a menu slides open and you move the mouse to “activate route”. This can be quite cumbersome when sailing, especially when you are doing so solo.

Now that you have the basic system and some nautical charts, you also want to be able to determine your position. There are GPS receivers available that can be connected via USB. Please note, the more USB devices you connect to the Pi, the more difficult it will be for your power supply. It is therefore often recommended to connect an extra USB hub that has its own power supply.

Before you can use the Pi on the boat, it must first be connected to a power supply. Unfortunately, a Pi cannot be connected directly to a 12 or 24 volt battery, but works on 5v. Not every boat is equipped with a 5v power supply that delivers enough amperage to provide sufficient power for the Pi. So you’ll have to turn the, say, 12v into 5v. This is done with a DC-DC converter, which is widely available online. The power supply must be able to deliver at least 3 amps to provide enough power for the Pi.

So far so good, if all went well you now have a simple map plotter for relatively little money.

Our journey was a few years and ships ago, how to activate ALL of that wonderful system Openplotter at once. We speak for ourselves and of course not for everyone, but maybe there are several people who experienced a similar journey.

In any case, we wanted a chartplotter with as many sea charts and details as possible to make a trip around the world. An autopilot that not only allowed us to maintain a magnetic or GPS course and make course changes, but also to draw complete routes that the autopilot would follow. Also, an AIS system that picks up other ships’ positions and other available information on them via VHF and displays it on the plotter.

We wanted to report our position to MarineTraffic for those at home. Monitor the temperature of the engine and the condition of the batteries. Digitally monitor the temperature and humidity of the cabin, as well as the barometric pressure. Digitally switch equipment such as lights and fans. Read out the depth gauge on the Pi. And much, much more…

In the end, we succeeded, but not without experiencing everything mentioned earlier.

As mentioned earlier, the possibilities are truly endless of what you can build yourself. You may enjoy this for years to come, but there are also circumstances that need to be taken into account:

• Humidity:
  On a boat, conditions are more harsh than in a normal home. There are many dry boats, but in general they can be rather humid. You’ll have to take this into account in your project. Most standard raspberry pi cases are not waterproof, so moisture can get into your electronics. There are housings available that are waterproof, but you will still need to somehow get the cables from the inside to the outside.
• Salty Air:
  The humidity at sea is accompanied by salt. Here, too, there is a risk to your electronics.
• Vibration:
  When the engine is running, the ship is vibrating and when you are riding the waves a bit more wildly, there are shocks. So you will have to make your solution more robust somehow. Often, when you expand the Pi with extra parts or modules, they are connected with plugs, connectors or jumper wires. Even if the connections seem tight, you can still get strange failures. You might lose GPS signal, or another sensor might fail, etc.

  Some of these failures can be avoided by using as little USB equipment as possible and soldering instead of using jumper wires. The ideal situation would be if all loose modules can no longer vibrate out of place. There are people who design their own panels for this, and assemble everything as neatly as possible to give it a permanent place on board.

On a boat, you often have less time to occupy yourself with complicated screens while sailing. This takes time and can be very distracting, in some cases even dangerous. Don’t get us wrong, open-source systems are of course fantastic because they offer so much functionality. Sometimes this just comes at the expense of the user-friendliness of the system.

Much of the functionality was originally developed separately and then added to the whole. This results in a lot of separate solutions from different developers, each with their own standards. You will therefore have to look carefully and critically at exactly what you want to use and when. Set everything up the way you want it in advance, so that you do not have to worry about it while you are on the move.

The more functionality there is, the more possibilities there are of something breaking. If you stick to the basics, nothing much is likely to happen. Do you do a system update? Then there is a good chance that the software you have updated now has a new feature or bug fix, but that another part of the system will fail.

Are you expanding functionality? Then more and more processes will be running on the Pi, which may at some point become too heavy for the little computer. As with updating, there’s a chance that when you install something new, something old will break. Do you feel like your system is stable and you’re happy with it? Then make a backup on a separate SD card. This way you can always quickly revert to the most stable version, in case something is broken.

Of course there is often a possibility to ask for help via various forums, or if you are handy with Linux you can still troubleshoot here and there and revert your last actions. But not everyone is able to do this. Most likely, the most simple solution is to change your SD card then so that you have a clean system again.

This is a subject that is hardly ever mentioned at the start of a project, but one that we would very much like to share.
On a boat, you’re actually used to just flipping the onboard switch when you go out, or if you turn off another device you can just press the off button. At home, too, you can often turn off your computer with a press of a button. If you’re really neat about it you go to “Start” to shut down.

With a Pi, it’s more complicated than that. If you don’t shut it down safely, there is a risk that your system will become corrupted and won’t start up again next time. It might work 20 times, but the day will come when you will have to replace or reinstall the well-known extra backup SD card. This is because SD memory was originally designed only for writing photos and videos and not for running a complete operating system. Another reason is that Linux has a different file system and is more sensitive to power failure.

So if you don’t change anything on your Pi then every time you leave your boat you will have to remember to log into the Pi first and shut it down safely. There may be an easier solution that does not require logging in. You can mount a button on the GPIO header (the row with 40 pins on top) with jumper cables so you can safely shut down with that button. This will not work immediately, you need to make a shutdown script first.

Another option is to use an SSD instead of a micro SD card. These can often be a little less sensitive, because in case of power failure they often have just enough internal power to complete a crucial writing action.

The best solution, however, is not to have to think about it anymore. To do this, you can extend the Pi with a UPS (emergency power battery), for example. This is a chip with a battery that detects when the power on the Pi is down. The internal battery then takes over and the system shuts down safely.

It all seems like a lot and maybe it is. We don’t want to intimidate or discourage at all. Because if you persevere and you like it, you will learn a lot about hardware and certainly about your own boat.

Even in the simplest scenario, you may have to buy duplicate parts, something may break or blow up. This may be due to your own error during assembly or due to other circumstances, or a part may not do what you want, or you may have the wrong part. In any case, it will happen one or more times that you have to order a part again.

Also with DIY solutions there are often more costs involved than you had anticipated. The simplest scenario will probably cost you around 100 euros. There are companies who have made it easy for you with pre-installation, but you may wonder whether you still have a robust solution. The most complete scenario will cost you at least 700 euros, if you do it right the first time. Let’s say you’ve made a few mistakes, 800 euros.

We have calculated that if you want to achieve anything like what the Openplotter software allows you to do with the products of leading brands, you will need to buy about 20 different devices. Each of these has to be placed in the ship, connected and communicate with each other. In the most modest scenario, this would cost around 17,000 euros. That is not even counting the most expensive equipment.

Of course, price is not the only difference. The proven brands deliver their products in robust housings, thoroughly tested and certified, and you also get warranty and support. Not everyone will buy all the equipment they want because of this.

Having experienced this journey ourselves, we wanted to enable other people to have all the technology they want, but in a simpler way, without all the prep work. That is why we created AyeAye®.

And after a few years of development and testing, combining all the technology into one integrated product, we are proud to say that we have developed a single, robust and intuitive all-in-one boat computer.

We want to give people access to open-source technology, but with robust and secure hardware. We want to give people access to all these different functionalities, but through a unified intuitive interface.

We want to show that not everything labelled maritime necessarily has to be overpriced.

The AyeAye® boat computer gives people access to open-source technology, but comes with robust and secure hardware that is certified for use in a maritime environment. The wide variety of features is controlled with the intuitive AyeAye® app. On your smartphone, tablet or laptop – available wherever you are.

The AyeAye® boat computer and app are adapted to the needs of modern boat owners who want to enjoy their time on the water the best way: without unnecessary worrying.