Pages Navigation Menu

Furuno GP1870F Fish Finder and GPS

Furuno 1870F
Furuno GP1870F GPS Fish Finder
Check Discounted Price
7"Standard Dual Frequency1200'Internal,

The Furuno GP1870F is one of the GPS / fish finder combos in the medium price and size range, which packs quite several navigational features specific to much larger units. Even though it’s not one of the fancy, touchscreen units released lately, this Furuno unit still is an excellent piece of technology, which can be invaluable on the water.

Technical Details and Specifications

  • Screen: 7″ diagonal, 480V x 800H pixel resolution, color TFT with a 65,000 colors capacity and LED backlight
  • Sonar: Dual frequency
  • Depth Capability: 1200 feet (365 m)
  • Frequency and Coverage: 50 kHz / 45° and 200 kHz / 11°
  • Transducer: 525STID-PWD, transom type
  • Power Output: 600 Watts (RMS)
  • Power Input: 12-24 VDC: 1.0-0.5 A
  • GPS: 50-Channel, Internal; 1 Channel SBAS
  • Maps: Basemap
  • Routes, Waypoints, Trackpoints: 1000, 30000, 30000

Transducer and Fish Finding Functions

Along with the core specifications mentioned above, there are quite several aspects to be mentioned about this unit. First of all, since this unit can work with various transducers, it’s often sold without one. The one reviewed here does include the 525STID-PWD transducer. This is actually a dual frequency transducer, and can be operated at 50 kHz and 200 kHz. The 50 kHz beam covers a wider and deeper water column, at a 45° angle and up to 1200 feet (365 m). The 200 kHz sonar beam is narrower, with 11° angle, but offers better detail, at depths up to 700 feet (213 m). Both frequency returns can be observed simultaneously in split screen, or independently, in split screen or not, with the charts view.

The transducer includes comes with 30 feet (9.1 m) of cable, and a temperature probe, which enables the unit to indicate water temperature. This also makes available the temperature graph function, which overlays onto the sonar, indicating the temperature fluctuations within different water substrates or spots.

Bottom lock and bottom discrimination are two useful functions specific to Furuno units. Bottom lock gives you a focus onto the water substrate near the bottom, aiming to help distinguish any fish that may keep close to the bottom. This is quite an effective function if you’re looking for bottom feeders. The bottom discrimination function analyzes the bottom echo of the sonar, categorizing the its hardness by one of the four types – rock, gravel, sand or mud.

One last aspect to be mentioned, regarding the fish finding capabilities of the Furuno GP1870F is the Accu-Fish function. This sonar function is similar to the Selective FishID+ from Humminbird units. It gives fish icons to the returns interpreted as fish, also providing an estimated size and depth of each one of them. It’s quite a suggestive features, easy to work it, helping you distinguish better between the bottom and fish.

Navigation Functions

The Furuno GP1870F is equipped with a 50-channel internal GPS receiver, offering fast lock, and accurate information regarding your position, also using SBAS for differential correction. The split screen function works for the GPS views as well, not just for sonar. Therefore you can view your chart in two levels of zoom simultaneously, for a better overview of your area. By moving the cursor on the map, you can view the coordinates of any particular point. This also includes the point of your boat.

The unit comes with a built-in basemap chart package, which provides basic information such as the outline of the coast, for example. However, this model is also compatible with C-MAP 4D by Jeppessen. This chart pack unlocks several very useful features, such as 3D chart view, satellite images with 3D and 2D overlay, and of course high-quality detail for all charts.

Amongst the navigation features of this Furuno model, there is also a route, waypoint and trackpoint function. The unit can store up to 1000 routes (50 waypoints each), and can store up to 30,000 waypoints in its internal memory. The waypoints function gives you the possibility to save all your favorite fishing spots on the map, or just about any point of interest that you may want to remember. Also, there is a track function, via which you can record your course. Each track can contain up to 30,000 track points. All tracks, waypoints and routes can also be backed up on a blank SD card.

The Furuno GP1870F sonar GPS combo also offers tide information, and the C-Weather function, two navigation function extremely useful especially for offshore anglers. The tide info function is quite easy to use. You simply move your cursor on your map, over the symbol of the tide station in your area, and access the full info on this matter. C-Weather, as terminology suggests, is a free service for Jeppessen Marine customers who use compatible technology. It offers weather coverage throughout the world, based on weather forecasts received from leading meteorological centers. To use C-Weather data, you have to connect your unit to the internet though, via the wireless LAN setup.

This unit is also AIS capable. Via AIS you can benefit from vessel information from all vessels within a 50 nautical miles radius. To become available though, this function requires an AIS module.

Other Features and Capabilities

This unit features a bright display, offering crystal-clear images, and being easy to read even in direct sunlight or if wearing polarized sunglasses, due to its LED backlit display. On top of that, the box includes sun cover. Also, its degree of protection is IP56, meaning that it’s dust tight and resistant to water spills.

It offers one SD card slot, which accepts SD and SDHC cards, for external storage of data. You can save map and sonar snapshots on your SD card, you can backup your trails and waypoints, or import them via a SD card adapter, into your computer.

It has a full range of alarms. For example, you will benefit from an anchor watch alarm, cross-track error alarm, depth, speed and temperature alarms, and of course, bottom and fish alarms.

This Furuno 1870F combo is compatible with various other transducers, not just the 525STID-PWD it comes with. For example, it can work with different 1kW transducer models, and if equipped with such a transducer, its depth capability can increase to 2500 feet (762 m).

Last but not least, this Furuno unit is NMEA 2000 compatible, for easy connection and superior integration possibilities into NMEA 2000 systems.


Of course, when compared with other units in this price and size category, there are a few minuses. This unit doesn’t have an ice flasher sonar function, which some anglers may prefer to the conventional sonar view, especially for ice fishing or stationary fishing.

There’s no sonar recording function, which also may be useful if you want to review sonar, or import the recorded sonar data on a SD card for use or storage on your computer.

Lastly, the 1870F GPS and sonar combo from Furuno is indeed an advanced unit, and it may take some time until you master it completely.


The Furuno 1870F combo is an advanced navigation device, offering quite a few sonar and navigation features that other units within this price range do not supply. It’s a great choice for any offshore angler due to its superior depth capability. Even though it doesn’t include sonar technologies such as Down Imaging, Side Imaging or CHIRP, it does compensate through is wide array of navigation and GPS features. It’s not exactly the cheapest unit that you can find, but it’s an investment worth every penny.


  1. ridiculously complicated to use

  2. My Furuno GP-1870F has developed a weak to no soundings condition. The unit has been working satisfactorily for previous approximately four years. Transducer and boat’s bottom are free of marine growth.

Leave a Comment

Your email address will not be published. Required fields are marked *