The Furuno GP-33 is not a chartplotter. It's the most common misunderstanding we hear about this box.
No chart, no card slot, no sonar, no radar overlay. You get a 4.3-inch color display, a 12-channel WAAS GPS receiver, and a network port that pushes a clean, stable position fix to everything else on the boat. That's the job. On the lobster boats and charter sportfishers where we've installed them, it does that job for a decade without anyone thinking about it.
This Furuno GP-33 review covers what the unit does, why commercial captains still bolt one to the overhead next to a big multifunction display, and the part most reviews skip: Furuno has discontinued it. We'll cover what that means and what we'd buy instead.
What the GP-33 actually is
Think of it as a dedicated position source with a screen attached. The receiver is a 12-channel GPS with WAAS/SBAS correction, which is good for roughly 3-meter accuracy when WAAS is locked (most of the continental US and its coastal waters). The 4.3-inch color LCD is rated at 700 cd/m², readable in direct sun but well short of a modern 1,200-nit MFD.
It stores 10,000 marks and waypoints, 100 routes of up to 30 points each, and 3,000 track points. Plenty for a boat running the same 40 string locations every week.
The part that matters most is the back panel. The GP-33 speaks both NMEA 2000 (through Furuno's CAN bus port) and NMEA 0183 (through a 10-pin connector that also carries a contact-closure output for an external alarm). That dual output is why it lives on so many work boats. It'll feed a new N2K backbone and an old 0183 radar at once, no gateway box needed.
| Spec | Furuno GP-33 |
|---|---|
| Display | 4.3" color LCD, 700 cd/m² |
| Receiver | 12-channel GPS with WAAS/SBAS (WAAS, EGNOS, MSAS) |
| Accuracy | ~3 m with WAAS, ~10 m without |
| Antenna | Passive GPA-017 style antenna, 10 m cable, 1"-14 thread mount |
| Outputs | NMEA 2000 (CAN bus) + NMEA 0183 (10-pin) |
| Memory | 10,000 marks/waypoints, 100 routes × 30 points, 3,000 track points |
| Display modes | 7, including 2 custom |
| Power | 12–24 V DC |
| Furuno MSRP | $745.00 (now listed as No Longer Available) |
A note on the antenna, since we get asked: the GP-33 uses a passive GPA-017-family antenna on a standard 1"-14 pole. It is not the Furuno GP-330B, which is a smart sensor with its own receiver inside. People mix up the "33" and "330" part numbers constantly. They don't interchange.
What "plotter mode" really looks like
The GP-33 does have a screen called Plotter. It shows your track, your waypoints, and your route legs on a blank background with a range scale. No shoreline. No depth contours. No buoys.
For a commercial fisherman who has run the same bottom for 20 years, that's all the "chart" he wants. For a recreational boater on unfamiliar water, it's a breadcrumb trail. Need a chart? Read our best marine chartplotters of 2026 roundup instead.
The highway and steering views are more useful than they sound. In 4-foot seas, a big cross-track-error bar you can read from 6 feet away beats squinting at a chart zoomed out to 20 miles.
Why a recreational boat would want one
Three reasons, and we've installed GP-33s for all of them.
Backup navigation that doesn't share a failure point. When your 12-inch MFD reboots mid-inlet (and they do, usually after a firmware update or a voltage dip on engine crank), you lose everything at once. A GP-33 on its own breaker, with its own antenna, keeps giving you lat/lon, speed, and course to the waypoint. That's what "commercial reliability" means in practice. Boring is the point.
A clean GPS source for the VHF. A DSC radio without position data sends its Mayday with no lat/lon attached. Wiring is covered in our guide on how to install a marine VHF radio. A GP-33 on the N2K backbone feeds position to a radio like the Icom M510 EVO with NMEA 2000 ($799.95) with zero configuration, and keeps doing it if the MFD is off.
Position for older radar and sounders. Plenty of boats still run a 10-year-old 0183-only radar. The GP-33's 10-pin output drives it directly. The Furuno NMEA 0183 10-pin cable for the GP-33 is $121.99 and is still in stock, which matters if you're keeping an existing unit alive.
What it can't feed
An AIS transponder does not use your GP-33's position for its own broadcasts. Class A and Class B transponders are required to use their own internal GPS receiver and antenna for the position they transmit. Our best AIS transponders of 2026 guide explains which units ship with that antenna in the box.
It also doesn't give you heading. The GP-33 outputs COG (course over ground), which is where the boat is moving, not where the bow is pointed. In a 3-knot cross current those can be 20 degrees apart. Radar overlay and MARPA need true heading from a compass or heading sensor. We've taken plenty of "my radar overlay is rotated" calls from owners who assumed GPS was enough.
The honest part: it's discontinued
Furuno now lists the GP-33 as No Longer Available and points buyers to the GP-39. Our Furuno GP33 Color GPS Navigator listing shows $651.99, but as of this writing it's out of stock and we don't expect new units to come back. New-old-stock GP-33s that turn up in 2026 run roughly $600 to $700. Working used units trade around $250 to $400; see one power up and lock satellites before handing over cash.
If you already own one, it isn't obsolete. Several GP-33 accessories are still on our shelf:
- Furuno NMEA 0183 cable 10P for GP-33 $121.99
- Furuno GPA017 GPS antenna with 10 m cable $128.99
- Furuno L-angle mount base No. 13-QA310 for the GP-33 $272.99
- Furuno flush mount bezel for GP-33 or RD33 (currently out of stock) $59.79
- Furuno pipe mount kit for GP-33 (currently out of stock) $55.09
The antenna is the part we replace most. After eight or ten years on a T-top the connector corrodes, and the unit takes 10 minutes to get a fix or drops to "2D" every time the boat rolls. Swap the antenna and cable before you blame the display.
The GP-39: the replacement, with one catch
The Furuno GP39 GPS/WAAS Navigator with 4.2" color LCD is in stock at $545.00. It's Furuno's recommended replacement, and mostly the same idea in a cheaper package: 4.2-inch color screen at 700 cd/m², the same 10,000-point waypoint memory, the same seven display modes, WAAS, and a tool-free "Click-In" bracket that makes swapping it between boats easy.
The catch is networking. The GP-39 is an NMEA 0183 device. There is no native NMEA 2000 port. If your boat is N2K and you were counting on plugging a navigator straight into the backbone the way the GP-33 did, the GP-39 needs an NMEA 0183-to-2000 converter to get there. That's added cost and one more box to fail.
On an all-0183 boat, the GP-39 is the better buy and it's $100 cheaper. On a modern N2K backbone, it's awkward. That one difference is why we still get calls asking for GP-33s.
If you go GP-39, the Furuno flush mount kit for the GP39 is $206.99 and a spare GP39 power cable is $96.29.
The cheaper alternatives: pucks and handhelds
Most recreational boats that want a "backup GPS" really want a second position source on the network, or a navigator that works when the boat's electrical system doesn't. Neither needs a GP-33.
GPS pucks (smart antennas)
A smart antenna has the receiver built in and puts position straight onto the backbone. No screen. If you only need to feed the VHF, AIS display, and autopilot, this is the cheaper, more modern answer.
- Furuno GP340 GNSS GPS receiver. Multi-constellation (GPS, GLONASS, Galileo, BeiDou, QZSS), 10 Hz, NMEA 2000 or 0183 via cable. The 6 m N2K cable for the GP340 is $104.59 and the 6 m 0183 cable is $75.09. $292.99
- Garmin GPS 24xd with heading sensor, NMEA 2000 (the 0183 HVS version is the same price). $253.99
- Lowrance Point-1 GPS/heading antenna $321.00
The GP340 is the one we'd pick in the Furuno family. Newer receiver, more satellites, under half the price of a GP-33. You lose the screen, and with it the "MFD is dead, where am I" backup.
A handheld in the ditch bag
The Garmin GPSMAP 79s handheld at $272.99 floats, runs about 19 hours on two AA batteries, and has a real 3-inch screen. The GPSMAP 79sc adds a camera for $315.99. It's the only option on this list that still works after the boat's batteries are underwater, which is the scenario a true backup exists for.
It won't feed your VHF or radar. We keep one in the ditch bag on our own boats regardless of what's on the helm.
How they compare
| Furuno GP-33 | Furuno GP-39 | Furuno GP340 (puck) | Garmin GPS 24xd (puck) | Garmin GPSMAP 79s | |
|---|---|---|---|---|---|
| Screen | 4.3" color | 4.2" color | None | None | 3" color |
| Receiver | 12-ch GPS + WAAS | GPS + WAAS/SBAS | Multi-GNSS, multi-band | Multi-GNSS, 10 Hz | GPS + GLONASS + Galileo |
| NMEA 2000 | Yes, native | No (0183 only) | Yes (cable) | Yes | No |
| NMEA 0183 | Yes | Yes | Yes (cable) | HVS version | No |
| Charts | No | No | No | No | Basemap only |
| Works without boat power | No | No | No | No | Yes (2× AA) |
| Price | $651.99 (out of stock, discontinued) | $545.00 | $292.99 | $253.99 | $272.99 |
Install notes from our boats
Give it its own breaker. A backup navigator on the MFD's circuit isn't a backup. We wire it to a separate 3-amp breaker.
Keep the antenna away from the radar and the VHF whip. Passive GPS antennas are sensitive to RF. Put it at least 3 feet from the VHF antenna and out of the radar's beam path. A GP-33 that loses its fix every time someone keys the mic almost always has its antenna sitting right next to the whip.
Don't create a position fight on N2K. With the GP-33, the MFD's internal GPS, and a puck all on one backbone, every device picks a source, sometimes the worst one. Set it explicitly on each display and the VHF. Our NMEA 2000 network setup guide covers source selection and the termination mistakes that cause dropouts.
Use the contact closure. The 10-pin connector can drive an external buzzer for anchor-drag or arrival alarms. Over a loud diesel, the built-in beeper is useless.
Four questions that decide it
Do you need a chart? If yes, stop here and buy a chartplotter. None of these units show one.
Is your boat NMEA 2000 or 0183? N2K backbone and you want a screen: a GP-33 if you can find a good one, otherwise the GP-39 plus a converter. All 0183: GP-39, no contest.
What does "backup" mean on your boat? If it means "the MFD crashed," a GP-33 or GP-39 on its own breaker solves it. If it means "we lost all power," only a handheld does.
Just need position at the VHF? A $254–$293 puck does it.
The bottom line
If you already own a GP-33 and it's working, keep it. Replace the antenna and cable when the fixes get slow, and it'll keep feeding your VHF and radar for years.
If you're buying new in 2026, don't chase a discontinued unit. On an NMEA 2000 boat, buy the Furuno GP340 at $292.99 as your independent position source and put a Garmin GPSMAP 79s in the ditch bag. That's about $566 for a better receiver and a real power-loss backup, which is less than a GP-33 cost new. On an older 0183 work boat where the captain wants numbers on a screen at the helm, the GP-39 at $545.00 is the straight replacement and it's the one we'd install.
Not sure which fits your wiring? Call us at (212) 688-0550, tell us what's on your backbone, and we'll tell you whether you need a converter before you order.
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Shop All Furuno Products at NVN Marine →Frequently asked questions
Is the Furuno GP-33 a chartplotter?
No. The GP-33 is a GPS navigator. Its plotter screen shows track, waypoints, and routes on a blank background with no shoreline, depth contours, or navigation aids. It's a dedicated position source and backup navigator, not a charting display.
Is the Furuno GP-33 discontinued?
Yes. Furuno lists the GP-33 as No Longer Available and recommends the GP-39 as its replacement. NVN Marine's GP-33 listing is $651.99 but currently out of stock. Accessories such as the NMEA 0183 10-pin cable and the GPA017 antenna are still available.
What is the difference between the Furuno GP-33 and GP-39?
The biggest difference is networking. The GP-33 has native NMEA 2000 and NMEA 0183 outputs, while the GP-39 is NMEA 0183 only and needs a converter to join an NMEA 2000 backbone. The GP-39 has a slightly smaller 4.2-inch screen, a tool-free bracket, and costs $545.00 at NVN Marine.
Can the GP-33 provide GPS position to my VHF radio and AIS?
It can feed position to a DSC VHF radio and to any display that shows AIS targets. It cannot replace the GPS antenna on an AIS transponder, because Class A and Class B transponders must use their own internal GPS receiver for the position they broadcast.
Does the GP-33 provide heading for radar overlay?
No. It outputs course over ground, which is the direction the boat is moving, not the direction the bow is pointed. Radar overlay and MARPA tracking need true heading from a compass or dedicated heading sensor.
What's a cheaper alternative to a GP-33 for a backup GPS?
For a second position source on the network, a smart GPS antenna like the Furuno GP340 ($292.99) or Garmin GPS 24xd ($253.99) is cheaper and uses a newer receiver. For a backup that works with no boat power, a floating handheld like the Garmin GPSMAP 79s ($272.99) is the better choice.
