AIS vs Radar. Chartplotter vs iPad. PBO reader asks: Should I replace my analogue radar and Raymarine C70 display with an iPad and AIS? It's £3,000 cheaper than a new digital radar and Axiom display!


I have a question I would be very pleased if you would put to your expert in electronics.

My yacht has an old Raymarine C70 and the screen has gone blank as if it has no power. I have measured 14V at the power plug (battery charger was on) so it does have power. Repairs to the C70 might be possible but it would still have 17-year-old components inside which may also fail soon. Good money after bad?

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I have had an estimate to supply and install a Raymarine Axiom plus digital radar (it won’t run my old analogue radar) for about £3,600.

But, as the GPS, depth and wind are still working, I am thinking of going down the route of installing an iPad mini (with GPS) plus a Navionics chart app and connected to an AIS receiver for about £3,000 less than the Raymarine Axiom and its digital radar.

So many vessels have AIS nowadays that we are not uncomfortable going offshore without radar.

It sounds simple but my question is, can it be done and what are the downsides, pitfalls etc.?

Retired Greenham Regis marine electronics expert Andy Haines responds:

This is a bit of a chalk and cheese question, or to put it another way, not comparing like with like, on two counts really. Firstly, comparing a proper marine product to a tablet and, secondly, comparing AIS vs radar. With AIS however, we need to point out, there are two choices, ‘receive only’ or ‘transmit and receive’ (Transceiver): I would advocate Transceiver every time.

Despite the above, it is a good question and one we are often asked.

Looking at the initial problem, yes the C70 is now getting on a bit, although my first reaction would be to try to find a good second-hand C70 or preferably C80, (which has an 8in screen as opposed to the 7in of the C70). That shouldn’t cost more than £400, maybe £450 and it’s ‘plug and play’. Assuming the original radar still works, would be a good outcome.

You can also add AIS to a C70/80.

However, if you feel it is time to move on, then fair enough.

You can have AIS on an iPad, no problem – some manufacturers make wireless AIS’s which can link by wifi to the iPad.

To answer the question – comparing an Axiom plotter-and-radar with an iPad-and-AIS – we have to firstly compare the Axiom vs iPad for chartplotting/GPS and then compare AIS vs radar.

Axiom vs iPad: One can argue both ways on this because in some respects, at first sight, there is little to choose one way or the other.

However, the Axiom is a dedicated piece of marine equipment, it is designed to run on the vessel’s 12V supply without causing interference, or being susceptible to interference (marine EMC [Electro Magnetic Compatibility] regulations are quite strict). iPads and mobile phones do not conform to those regulations.

Marine products are more expensive than domestic products for this very reason, regulations are much stricter, plus they have higher quality daylight viewing screens and are waterproof. There have been and still are concerns about non marine devices which don’t comply to the stricter marine regulations potentially causing interference to say an autopilot or vessels radio.

An iPad is hard to see in the daylight, let alone bright sun and an iPad is not waterproof.

If you register your purchase online with Raymarine you get a 3-year warranty, I would imagine the iPad is 1 year.

Personally, I would opt for a dedicated marine product every time, but I dare say there will be people who disagree. You wouldn’t purchase a standard road car to plough a field, you’d buy a tractor, designed for the job!

The next point is, AIS vs radar: This really is chalk and cheese, they are two completely different products, both have their own merits. AIS is brilliant, easy to use and accurate, with almost no room for user misunderstanding. Radar admittedly does take more understanding and user interpretation, BUT, radar will see the vessels that don’t have an AIS Transceiver. It is only compulsory for a vessel to transmit AIS if it is over 300 tons, so, that means in fog you may not know that a 290 ton vessel without AIS was about to mow you down, whereas, you would almost certainly see it on a radar. Admittedly, it is unlikely a vessel of that size wouldn’t have AIS, but it is still a valid point to make in favour of radar.

However, if you have an AIS Transceiver it is fair to say that other vessels will see you on their plotter if they have AIS, so this is a huge advantage. Ideally, have both AIS Transceiver and radar if you can. However, we are seeing more and more people opting for an AIS Transceiver as opposed to a radar, partly because it is cheaper, partly because it is easier to install and use and you don’t have to have a radar dome on the mast. Also, the massive comfort factor of knowing that other vessels with AIS can see you is a very strong argument.

Conclusion (in my opinion):

· Best choice, a proper marine plotter, say an Axiom, but there are plenty of good other makes, a radar and an AIS Transceiver.
· Joint second choice, Axiom plotter and radar or Axiom plotter with AIS transceiver. This is always a difficult one, there are swings and roundabouts as mentioned above, the cost and the benefit of transmitting AIS data does come into it.
· Third choice, iPad/tablet with AIS Transceiver.
· Fourth choice, Axiom plotter with AIS Receive only.
· Last choice, iPad with AIS Receive only.

Note: I feel the AIS Transceiver is actually more important than the plotter, which is why I have placed it third, above an Axiom with AIS Receive only – at least other people will be able to see you (if they have AIS), even if your iPad goes flat or you can’t see it in the sunlight.

The obvious thing to point out about the above is that first choice is the most expensive and last choice is the cheapest.

In essence I cannot advocate a non purpose built marine product, but I do see the attraction.

I would make one final point: nobody ever regrets spending more money six months down the line, but many regret opting for the cheaper route once they’re living with the decision they made.

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