Legacy GPS: repair or replace?


Many cruisers are seeing their legacy permanent-mount GPS units gradually fade, wither and succumb to an ignominious death. But death often comes slowly, the gray LED screen sometimes fading out for a few hours and then suddenly springing to life with the correct course and full data recovery, only to tire of its work and fall back to sleep until it’s ready to wake up again.

Some cruisers attempt to replace the internal battery in, say, a legacy Garmin GPS 128, a wildly popular device 15 to 20 years ago. You will find sailor blogs directing you to cut open the sealed casing, pry the old battery free of its soldered wiring and then re-solder the wires to a new battery. You cross your fingers in hopes you have found a battery more or less of the same specifications as the original, and pray you will not destroy the battery with the searing heat of the soldering iron.

The other option is to face reality and embrace the latest array of permanent-mount GPS units available on the market. Which brings us right back to the reason many skippers prefer their older units: simplicity in design, ease of use, the absence of distracting color graphics and no depth sounder/fish finder or other bells and whistles some mariners find annoying. After all, we’re sailors, not commercial fishing crew.

If, on the other hand, you are looking for a multifunction navigation system with color graphics and the obligatory depth sounder transducer included in the box (requiring you to drill another hole in the hull), many high-quality options abound from Garmin, Raymarine, Simrad, B&G and other manufacturers.

Currently, only one major electronics manufacturer — Furuno — offers a simple, well-designed, solidly built GPS unit along the lines of the classic Garmin GPS 126 and 128. Though many of us associate Furuno with upper-end radar systems and multifunction navigation consoles, they also offer the small, reasonably priced GP33, which is similar in size and function to the Garmin GPS 126/128 but also offers a rudimentary graphic course display. The GP33 operates with a highly sensitive 12-channel receiver capable of storing up to 10,000 marks/waypoints, 100 routes and 3,000 track points.

You can install the GP33 as a stand-alone device or network it with your AIS unit and other inputs. The device supports both NMEA 0183 and CAN bus interface, which is a communication protocol connecting various inputs through a single “backbone” cable.

The GP33’s basic navigation screen displays latitude and longitude, heading, bearing, vessel speed, course, date and time. The “Highway” screen shows the vessel’s true course and heading with relation to the bearing.

Rather unique to the GP33 and not found on older GPS devices is a compass screen displaying a circular digital compass card, permitting natural intuitive viewing of the heading rather than an isolated number appearing on the screen.

A simple graphic plotter allows you to follow the vessel’s progress through a set of waypoints. The unit does not include navigation charts, but you can interface the unit with a multifunction chartplotter or simply plot your points on paper charts, just as you may have done in the past with the Garmin 126/128 or similar technology.

If you consider Furuno’s reputation for quality and the GP33’s price of around $500, this is really a great deal if you want the simplicity of a basic GPS without the bells and whistles of the more sophisticated systems.

Circumnavigator-author Bill Morris is the author of Sun, Wind, & Water: The Essential Guide to the Energy-Efficient Cruising Boat and is a frequent contributor to Ocean Navigator.

By Ocean Navigator