Marine Electronics

VHF radios for the run past phone signal:

a few miles out from Bahía Drake the phone goes quiet, and the radio becomes the way to reach other boats and the shore. A fixed-mount set wired to the boat’s battery has several times the power of a handheld and, with its antenna mounted high, reaches far enough for the boats running out to the offshore banks. A floating handheld from Standard Horizon or Icom suits a panga with no real electrical system, and backs up everything else. On either kind, look for DSC with built-in GPS: one button sends a distress call with your position. Some fixed radios also receive AIS and put the cargo ships working in and out of Caldera and Moín on the plotter screen.

Chartplotters, sonar and the network between them:

a modern helm is one screen doing several jobs. A chartplotter or multifunction display draws the chart, shows the sonar and overlays radar, and the dedicated units for each job sit under GPS and radar and fishfinders. What ties it together is the network. NMEA 2000 lets a Garmin radio, a Raymarine autopilot and a Yamaha outboard’s engine data share one backbone, but radar, sonar modules and display-to-display links run on each maker’s own network: Garmin Marine Network, Raymarine’s, or the Navico one behind Simrad, Lowrance and B&G. A used radar of another brand rarely joins your helm. Older gear speaks NMEA 0183, wired terminal by terminal, and needs a converter to reach a newer backbone. An autopilot’s compass has to sit clear of anything magnetic and be recalibrated whenever it is moved.

US charts on a Costa Rican boat:

plotters sold in the United States usually come loaded with US inland or US coastal charts, and neither shows the reef at Cahuita or the rocks around Isla Tortuga. Outside that region you get a coarse world basemap, no use for finding a channel. Garmin and Navionics sell a Central America and Caribbean chart, on a card or as a download, that covers both of the country’s coasts, so ask whether one comes with the unit and when it was last updated. A plotter listed as “with charts” may only have the ones for Florida.

Sun-browned screens and radios set up for another boat:

power the unit up in daylight before you pay. A display left uncovered in the sun can brown out, and on many units the screen and its board are one part, so the repair is a replacement. Fogging behind the lens means air and moisture have got between the glass and the LCD, and on some Garmin displays a black border that lightens or bubbles shows the glass starting to delaminate. Pull the power and data plugs and look for green corrosion on the pins, and ask whether the bracket and power cable come with it. A DSC radio may still hold the last owner’s MMSI number; on Standard Horizon sets it can be entered only once, so changing it means asking the maker for a reset code. With a handheld, ask for a radio check with another set and find out how old the battery is.

Photos of a lit plotter and the plugs behind it:

the screen switched on with a chart or sonar page showing, then the back with every plug in view, because a buyer is judging both. Give the full model name, not just the brand, and list what comes with it: transducer, mount, cables, sun cover and the chart card with its region. Say whether it speaks NMEA 2000 or 0183, whether it ran on a networked helm, and whether a radio still carries your MMSI. Say whether it came off working, after an upgrade, or because something failed. A tarpon guide in Barra del Colorado, who goes by boat before he even reaches a road, wants to see the plotter lit and the card’s region before making that trip, so put both in the first photos.