Tried and true is a useful criterion for standards. I still require two-person watches when our boats run in restricted visibility, where one of the two watchstanders must be a capable radar operator, primarily responsible for the radar watch.
That operator has often been trained, as was I, on something like our classic Furuno large vessel radar, where ARPA and similar semi-manual processes are used to avoid collisions. I, some of our captains, and other senior operators have been less comfortable with the busy nature of a modern AI-aided Doppler overlay on a chart plotter, where warnings are generated by the combination of MARPA, AIS, and relative movement from Doppler or comparison to chart and GPS information.
Many of us are less comfortable with modernity, but I remember the limits of a pure radar watch.
Years ago, when radars were already accurate but LORAN C was less so, close-in navigation often depended upon a good paper chart and the ability to recognize fixed radar targets to obtain a fix. That worked well when departing Onset for Boston in a dead fog by picking up the buoys in the Onset channel.
However, the sharp turn to port to transit the Cape Cod Canal did not work well. The strongest stationary target in that direction turned out to be an aluminum dinghy anchored over the shallow water to the left of what is now Green 23, whose light and sound were distorted by the dense fog.
I chose the stronger target and went gently aground, so we set an anchor to await the incoming tide and made certain that our anchor light and horn were operating properly. I spent the next hour on the radar watching the aluminum dinghy depart and trying to improve my ability to distinguish between the target returns of metal dinghies and large buoys.
I had been monitoring Canal Control and was thus aware that a large ocean-going tug with a barge on a relatively short tow was about to make the turn after the maritime academy, so I began to track the tug on my radar. I suddenly realized that he confused the return from our vessel with that of the buoy we had missed and that he was bearing down on us.
I immediately sounded the horn, tried to raise him on the appropriate channels, and finally saw the tug turn hard to port. Unfortunately, the momentum of the tow kept the barge heading directly toward us, and it was not clear that the tug could divert it in time or that the barge would be stopped by the shallow water.
We were on deck, preparing to abandon ship, and saw the bow of the barge towering above us when the tug finally was able to bring her off. Later, the rising tide and a local sheriff’s boat helped us get off the sand bar, chastened but unharmed.
I tried thereafter to be better at distinguishing targets, but a similar confusion occurred later with that radar on that vessel in similar conditions on Joppa Flats while trying to enter Newburyport.
That was many years ago, but we remember best the lessons learned from mistakes. I have no objection to a radar watch on a pure radar, but I now strongly recommend the concurrent use of the more modern displays, which have many more ways to define a target. Modernity drags us along, and old dogs must learn new tricks.
Melvyn Miller is an American yacht owner from the U.S. East Coast. He has owned and operated yachts for six decades and employed crew for more than 30 years. Comments on this column are welcome below.