DIY £200 chartplotter

John Calton builds his own 10in touchscreen chartplotter with GPS and AIS for a fraction of the cost of an off-the-shelf system

- John Calton

Having had two new knees, my wife decided after 40 years to give up the dubious pleasure of sailing with me. So, we sold our 10m boat and I bought a little Beneteau Antares 620 to allow me to remain afloat and catch some of the dwindling fish stocks in the Solent.

During all those decades, I appreciated the use of various electronic instruments that assisted my navigational skills. But I couldn't justify spending over £1,000 for the latest touchscreen chartplotter because it would be uneconomical for a 20ft boat that only, at most, coastal hops.

However, the convenience of instantly knowing where you are and whether a large vessel is bearing down on you when a blanket of fog descends meant that an up-to-date chartplotter was essential for my peace of mind.

My priorities were: it should have a 10in sunlight viewable touch screen; it should display Admiralty charts, to correspond with my Admiralty paper charts; it must display AIS images, as I'd found that over the last 10 years I was using AIS in preference to radar; it has to work on a 12Vpower supply and be affordable, and it must have a GPS receiver embedded.

Dead ends

I've had the excellent Memory Map program on Windows XP for 10 years, as a backup to the Navionics charts on my last boat. So I thought I'd just update it.

I then encountered my first dead end: Memory Map does not include AIS, unless you buy the 'Pro' version costing approximately £150 per annum. My old notebook was fine for running Windows XP, but the poor screen and battery life let it down, while my old laptop was just too bulky and, again, has a poor screen and battery life. The latest Navionics program for my old Lowrance Elite 5 fish-finder would cost in the region of £170. And on top of all that I'd have to buy an AIS receiver and aerial. I decided it wasn't worth it for a poor 5in screen.