Children of the Magenta

I have been a navigator all my adult life. I was a deck officer in the Merchant Navy in the days when coastal navigation was done by taking bearings of lights, buildings and even trees; deep sea, we used sextants and wind-up chronometers. If it was cloudy, we were sometimes using ‘dead reckoning’ for days on end. There were some electronic Nav Aids, but they were inaccurate and unreliable. The first satellite system used single transits and you were lucky to get a fix every 20 minutes or so. I then became a commercial helicopter pilot. Officially, we navigated by ground radio beacons, NDBs and VORs. In fact, the aircraft were fitted with smart boxes which interpreted Decca signals to fly us from waypoint to waypoint, but signals were frequently lost and large jumps encountered switching from one chain to the next and we always monitored the fixed aids. The more experienced the pilot, the less inherent trust he had in the automatics. There is a, possibly apocryphal, story of a new airliner reaching a waypoint and, instead of turning left as expected, it turned right. Within two minutes, the tech savvy Co-Pilot had worked out why this had happened; within 2 seconds, the Captain had disconnected the auto-pilot and corrected the course.

With the introduction of GPS and ever more sophisticated navigational aids, an airliner can fly itself from take off until landing; even a helicopter can manage, while above about 80 knots, with just the occasional push of a button. The system is so accurate and reliable that there is a temptation to let the system do the work and relax the monitoring: as long as the aircraft is following the magenta line on the flight management system, all is right with the world. This works most of the time but just one little error in route entering can spell disaster. The older, more experienced, generation fight against this tendency and use the pejorative phrase ‘Children of the Magenta’ to describe pilots who blindly accept what the system is telling them without cross checking other sources.

My third age of navigation has been sailing. When I first re-started, in 2010, I used paper charts. Fixes, using a hand compass, were taken at appropriate intervals and plotted. Transits and clearing lines were employed. The log recorded waypoints passed. Our chartered yacht might have a chart plotter, but this was strictly back-up to ‘proper’ navigation. Even when we bought Ruby, we ensured that we had the best paper charts for the area and plotted our positions. As time passed, and we gained more confidence in our chart plotter, we progressed to just having sufficient paper to ensure that we could make a safe harbour if it failed. Then to having back-up electronic charts on the phone. Our positions are logged by lat / long, directly from the GPS.

The last few months have been spent in the Bahamas. While the water on the Atlantic side and between islands is many thousands of metres deep, the banks are very shallow with, in places, many coral heads. At first, we took them at low speed with a look-out on the bow but have now got used to sailing for miles with only a few feet below us. The only charts that our, 12 year old, chart plotter will load are supplied by Navionics. These have a reputation for poor coverage in this area so we have used them with caution. On passing through in the Spring, I purchased Wavey Line charts for my phone. These are good, but are not, unlike Navionics charts, stored on the phone, so require internet access, so may fail in inaccessible areas. Following our grounding in January, I also purchased Explorer charts for the phone. These are regarded as ‘Gold Standard’ but this ap has also let me down by freezing at times. What these charts do have is a plethora of waypoints linked by known tracks. I have no reason to believe that these tracks, apart from where they weave between specific charted dangers, are any deeper than anywhere within a few hundred metres. What they do bring is the knowledge that dozens, or hundreds, of other yachtsmen have followed them and, if there any rocks to be found on them, someone will have done so.  While paper charts are available, for vast areas there is nothing to take bearings from so one could only take satellite positions and plot them, something tha a chart plotter does automatically.

Accordingly, we now transfer the waypoints to our main plotter (treble checking each one) and sail or motor along the lines. It works, but I am not proud of this lowering of navigational practice. I have become a Child of the Magenta.