Electronic navigation aids.

The essential guide to what's useful and what is just plotter dressing.

Its been coming for a long time, the demise of the analogue systems and their replacement with digital systems, everything controlled from a touch sensitive screen, all working in blissful harmony, well that´s the theory, the reality is quite something else. I want to make it clear, I am no luddite, part of what I do is keeping up to date with the latest electronics and digital systems, I am however cautious and also notoriously frugal.

There's no doubt, at the boat show or in the showroom, when you can see the screen easily and can control everything at the touch of a button it makes a convincing case for itself, also lets not forget that the strides in electronics have definitely made boating, navigation in particular easier and safer. Each boat is different, each clients needs different and also each budget is different, so lets start having a look at what's going on.

I am going to break down this subject into two parts, aids to navigation and then everything else, at the time of writing I cannot possibly cover every single piece of kit or how it works or evaluate it, so I am going to concentrate on the mainstream devices, things that we fit a lot or come installed on new and used boats.

Aids to navigation or, what I need vs what's nice to have.

You have to imagine being on the water, really and truly what is the critical information that you need to help with navigation. I find most people have their boats heavily overequipped for the type of boating they do, never far from land, during the day in calm weather and I can´t say as I blame them. The newer the boat the more often the newer the navigation systems on board, so lets have a look at what's what.

GPS

This is a most often misused term, GPS stands for Global Positioning System, it has its origins in the defense industry, In itself all GPS does is give you a position, a latitude (how far north or south of the equator) and a longitude (how far east or west of the Meridian line), so unless you can interpret these coordinates quickly the information might not be that useful, its when a GPS antenna is interfaced (or built into) a chartplotter that it becomes really useful and forms the basis of essential aids to navigation. An example of where you will still find standalone GPS antennas is on a lot of VHF radios, the position is information is critical and so a redundant system is used to only supply positioning to the VHF.

Chartplotter

The chartplotter is what forms the base of the system, the newest screens can be used to control everything from pumps, to lights, to navigation systems and music. In essence a chartplotter works with a digital nautical chart and a GPS to draw a picture on the screen telling you where you are in relation to the surroundings, a bit like in car navigation but for the sea. You buy chart cards for the area you are navigating in (some are in built or at least a worldwide base map), the chart cards come in various levels of information but for the purpose of this article they are a digital version of the paper charts we used (and still do) for years.

From the information provided by GPS, the chartplotter shows you exactly on the screen where you are, the bigger the screen the easier it is generally, other essential information includes (electronics love acronyms, so here goes), SOG (speed over ground), COG (course over ground), so straight away we can see where we are, where we are going and how fast we are doing it, marvelous, even the cheapest models on the market will do this. I wont get into all the other stuff now about what a chartplotter will do but it´s the backbone of your aids to navigation system, you can have multiple screens on a network and you can select what you want to see on each screen.

Depth

Essential information, how much water is underneath you, called a sounder as depths marked on nautical charts are called soundings, sonar is an acronym for Sound Navigation and Ranging and it´s the instrument used to measure depth of water. In their simplest form, depth sounders just show a depth of water immediately under the sensor (called a transducer) installed on the boat , a more complete system would be able to distinguish bottom composition (i.e. Is it rocks, sand etc.), water temperature and are capable to showing the depth of much deeper water.

Fishfinders can tell you how deep the fish are and how big they are. One system I got to test quite a bit was forward facing sonar, this has a special kind of transducer that faces towards the front of the boat and gives you the depth and bottom contours in advance to avoid running aground, where this particular client uses their boat I can definitely see the benefits. A lot of the newer charplotters already have fish finders installed as part of their software, only the transducer must be installed and connected for it to work.

Radar

Another piece of kit, another acronym, radar is Radar Detection and Ranging, it was invented around the turn of the twentieth century and has been in use ever since. Radar assists in navigating in poor visibility, busy areas or at night, a lot of larger boats will have it running during the day also, radar antennas spin around looking for objects around you (contacts), these contacts are then drawn on the screen to show you what's around you. Some systems have a really useful feature that allows the radar to picture to be overlaid of the electronic chart, telling you what the radar has detected and helping distinguish between fixed objects on land and things afloat.

If you already have a quite modern chartplotter, you can probably buy an external antenna radar and connect it, for older plotters you could buy a new old stock antenna or a secondhand one, the alternative to finding one compatible with your existing system is to buy a standalone system.

Autopilot

As it name suggests, it is used to maintain a course automatically. It comes in very useful on longer journeys, a lot of modern propulsion systems that have joystick control have autopilot incorporated, even on small open boats. Autopilot is a terrific aid when going on long voyages. On recreational craft it should not be used to avoid collisions, this is still the responsibility of the person at the helm.

AIS (Automatic Identification System)

If any electronic navigational aid has helped more than any other its AIS, for a look at what it does, go to www.marinetraffic.com and you will be able to see all the vessels equipped with AIS, some of them will have file photos, details of the ship, it´s route, it´s ETA at destination etc. Whilst this sort of information is mostly for the professional mariner and large ships, it does not take away from it´s usefulness to smaller craft.

AIS comes in two types, the ability to receive AIS only or the ability to receive and transmit your own details (position, speed, COG) to other equipped vessels. AIS works on the VHF band of frequencies, some VHF radios have built in AIS, something to think about if you are upgrading your radio. Standalone AIS receivers and transceivers are available and can either have their own antenna installed externally on the boat or a splitter is used to share the VHF antenna.

VHF radios

I have deliberately left this until last, the humble VHF radio, radio communication was invented by Marconi and was rolled out for use on ships and shore stations in about 1900. It is tried and tested technology that is still used today.

• Summoning assistance, including life saving help.

• Weather and navigational information.

• Communication with other boats or ports.

VHF radios are probably the most important piece of electronics kit on board, also the most widely misunderstood, typical quotes about them include;

“I don´t need one, I´ll just call you on the phone”, aha, if I don´t answer, then what?

“I don´t need one, I have a walkie talkie”, okey dokey, good luck with that.

“I don´t know how it works”, it´s very easy, I'll show you.

I could go on but you get the idea, so what is the primary use of the VHF radio? The first and last points are of particular importance, obviously the ability to summon help is paramount (don´t worry, in the grand scheme, boating is quite a safe thing to do), VHF radio is monitored and calls for assistance will take priority. On a phone you would normally speak to one person at a time or maintain a two way conversation, on the radio you can summon assistance from everyone within range, increasing your chances of getting help.

Communication with ports, this came up quite recently, a regular visitor to one of the marinas in Gibraltar was quite shocked when he got quite the dressing down for not having a VHF radio installed and it was protocol to communicate via this method and not mobile phone, very soon afterwards a VHF was installed. I do understand the marinas point of view, especially on a 35 footer, not even a handheld VHF was on board. Using a phone as primary means would mean either giving out a personal number or having a dedicated office or company phone and all that it entails.

We have looked at what is really needed (or at least the important items), its up to each boat owner to decide what they will or will not install, going on my experience with most owners, the most minimal should b enough, I would always say a VHF radio, if you don't want a fixed installation, then a handheld one.

Other stuff (or what the factory installed)

I am no stranger to the electronicary (newly invented word) of things on boats, I am not however, a designer or sales and marketing type, so a lot of the options (and their associated prices) seem strange to me, but judging by the number of people who tick the boxes, I am obviously in the minority, so here we go.

Courtesy lights

I don't mean the original ones like you see everywhere, located at ankle level and designed so as not to distract when driving at night but to provide enough illumination when moving about in the dark so you don´t bash you toes in or not see a split level cockpit. Enter the world of disco courtesy lights, strips of lights (with a color controller in some cases), under seating, under storage, in hardtops, around doors, wherever it´s possible to install a strip of LED lighting. It doesn't stop there, how about lights in the cup holders and of course in the speakers.

I have to admit it´s amusing, for a very short while, going from the cool colors of Blade Runner to a full on Ibiza house party, then back again like tripping out with Alice in Wonderland, some of the boats would give Tokyo, Times Square or Piccadilly Circus a run for their money. The problem is I don´t see the value in it, it´s amusing in a fun fair sort of way but unlike a thumping stereo for playing your tunes, flashy lights do little else, they´re not good for reading, you probably wouldn't want them on when navigating and you certainly wouldn't want to go to bed leaving them on their red setting!

One other thing, whether it´s the port operatives being killjoys or one of the rules in the berthing contract, sooner or later you will be asked to turn them off or turn them down.

Stereos

In a word, streaming, mechless systems are the new norm, wireless connectivity via Bluetooth, Wi-Fi or a dedicated app. This is the new norm and I like it, subscribe to any one of the apps for music and the catalogue is immense, changing the radio cassette (showing my age but we still call them that to distinguish between music and VHF radio) to a newer streaming capable unit is a very popular and worthwhile upgrade. I will be writing an article in the future about this.

Some of the units are capable of being connected to the network that your chartplotter screen is on (NMEA2000) and audio control can be done from there. This can be useful when the stereo is fitted away from the dashboard and no remote control is installed.

Of course no stereo would be complete without an amplifier for that full on “thump, thump” bass. Actually because speakers operating in exteriors of boats have a lot of free air, an amplifier makes a huge difference to the sound quality, the physically small stereos can only provide so much power, they won´t distort but simply run out of oomph to overcome the noise of the engine and the air as you drive along. Read my post on installing an amplifier here.

Engine information

Electronics used for viewing engine information have been around for a long time, MAN and Caterpillar diesel engines have had digital gauges and LCD screens for years, this is now taken to the next stage where in many cases there is not a single analogue gauge anywhere (well, they´re probably digitally controlled anyway but they look like old school gauges).

I have to admit to having been skeptical at first about this part of the electronic changes but I am happy to have been proved wrong because it has turned out to be mostly very reliable and has the benefit of being able to see what information you want in the format you like it. In fact the levels of customization of information are amazing, big digits, analogue, combinations of the two, Simrad are particularly good at this.

Other advantages I have noticed, alarms and error messages, alarms can be configured with sounds and visuals on screen, lets be honest with so many things being so reliable now, we have been lulled into a sense of not keeping an eye on gauges, so when something is not as it should be and an alarm or error message appears, it at least should give you an idea of what's up and how critical it is, this is especially useful when service calls are made as we can inform clients of what to do.

But how can I get my engine information on screen I hear you ask, well actually its quite straightforward, a lot of engines already have electronic boxes or gateways available for them, some are made by the engine manufacturer themselves, Mercury Vesselview Link is one example, others are made by specialist electronics companies, these gateways convert engine data into data that goes into the network and then can be seen on the chartplotter or other screen connected to the network.

“But my engines are so old, there’s nothing even remotely electronic about them”

Fear not, solutions are available, there are converters that can turn analogue signals into digital ones and send them to the network. This is particularly useful on older boats and I will explain why, basically they were designed in a different time where large screens or indeed multiple screens were not the norm and so valuable dashboard real estate is taken up by gauges and switch panels, especially when you have a flybridge vessel where often the raised helm on the flybridge is quite small, so a gateway can be installed and a raft of the analogue gauges removed and a screen fixed in their place.

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