Marine Electronics

The VHF radio and what gets wired to it:

nearly every boat carries one, either a handheld or a fixed set on its own antenna, and DSC on a fixed set adds a distress button that sends your position with the call. AIS shows nearby ships with their course and speed, and a transponder also puts your boat on their screens. An autopilot holds a heading so the helm is free: on a tiller sailboat it is a small ram clipped to the tiller, on a wheel a belt drive, and on a heavier boat with hydraulic steering a pump below deck. Displays from Garmin, Raymarine, Simrad and Furuno tie it together. Sounders and transducers sit under fishfinders, and plotters, antennas and scanners under GPS and radar.

AIS among the ships off the Canal anchorages:

off Panama City and outside Colón, ships lie waiting their turn, and a small boat crossing them at night or in a squall is hard to pick out from a bridge high above the water. That is the case for AIS here. A VHF with a built-in AIS receiver is the cheapest way to see the ships; a class B transponder lets them see you too, and needs its own GPS antenna plus a second VHF antenna or a splitter. With the radio itself, range depends far more on antenna height than on the set, so a fixed radio on a tall antenna reaches well beyond a handheld, which earns its place as the backup in the dinghy or grab bag. Size an autopilot to the boat’s loaded weight and its steering, not to its length.

Cheap radios and the autopilots that keep their value:

a handheld VHF runs about $130 to $200 new in Panama and a fixed DSC radio roughly $300 to $500, more with AIS built in. Used radios fetch a good deal less, because a new handheld costs little enough that few buyers gamble on one nobody has tested; what holds the price of a used set is proof it has been tried on air, with its microphone, bracket and power lead in the box. Bigger kit behaves differently. An autopilot or radar whose maker still supplies parts and software keeps much of its value, while an older plotter whose chart cards are no longer made drops to a fraction of what it cost.

Lightning, damp and a stranger’s MMSI on a used set:

the wet-season storms here carry a lot of lightning, and a strike or near miss on a mast can kill every set aboard at once, or leave one that powers up but no longer transmits, holds a GPS fix or talks to the network. Ask outright whether the boat was ever hit, and test more than the power button: call for a radio check, let the plotter find its position, move the autopilot drive from its control head. Look for scorch marks behind the unit, fog trapped behind the glass and dark patches on a screen that sat years in the sun. A radio may still carry the last owner’s MMSI, which its DSC calls would send; many sets accept the number only once, and changing it is a dealer job.

Photos of the back panel and the software screen:

they tell a buyer more than any description, so photograph the unit switched on with its software version or self-test screen showing, then the back panel and every connector, because a buyer needs to know whether it speaks NMEA 2000, the older NMEA 0183 wiring or a maker’s own network. List what goes with it: bracket, sun cover, power lead, antenna, transducer, heading sensor. Say whether it was ever aboard a boat that took a strike, and whether an MMSI is already entered. Someone driving to Pedregal to collect an autopilot will want the drive to suit their steering and every part in the box, because a pilot without its heading sensor cannot steer at all.