The HELIX 8 CHIRP MEGA DI GPS G4N is one of the new fish finders released by Humminbird at the end of 2020. Although it’s almost the same as the last year’s HELIX 8 CHIRP MEGA DI GPS G3N, it has several extra features. For example, it has built-in Wi-Fi, built-in NMEA 2000, and is compatible with the new CoastMaster charts. For reference, this is the Humminbird part number 411340-1.
Key Features and Specifications
- Display: 8″ diagonal, 1024H x 600V pixel resolution, WVGA 16-bit color TFT, with LED backlight
- Sonar: Dual Spectrum CHIRP, CHIRP Mega Down Imaging
- Transducer: Transom XNT 9 HW MDI 75 T
- Frequency and Coverage:
2D Narrow Mode: 180-240 kHz / 25°
2D Wide mode: 140-200 kHz / 42°
2D Full mode: 150-220 kHz (adjustable) / 42°
Down Imaging: 440-500 kHz / 45°
Mega Down Imaging: 1075-1150 kHz / 75°
- Depth Capability (with the included transducer):
Dual Spectrum CHIRP: 1,200 ft (365 m)
Down Imaging: 350 ft (106 m)
Mega Down Imaging: 125 ft (38 m)
- Power Output: 1,000 Watts (RMS)
- Power Input: 10.8-20V DC
- Power Draw: 1 Amp
- GPS: Internal
- Cartography: Humminbird Basemap
- Routes, Waypoints, Tracks: 45; 2,750; 50 (20,000 points each)
Sonar and transducer
The Humminbird HELIX 8 CHIRP MEGA DI GPS G4N makes available two sonar technologies, Dual Spectrum CHIRP (2D) and Down Imaging, with the Mega DI mode. It supports multiple base frequencies, including 50/83/200 kHz for its 2D standard CHIRP sonar, and 455/800/1200 kHz for Down Imaging. However, since it’s a Down Imaging only unit, it does not support MEGA 360 Imaging or Side Imaging.
The unit comes with the XNT 9 HW MDI 75 T transducer which supports both sonar technologies provided by the unit. It also has an internal temperature sensor, comes with a transom mount, and has 20 ft. (6 m) of cable.
For Down Imaging, the transducer uses oval beams. The coverage of the 455 kHz (440-500 kHz) beam is 45° and its max. depth range is 350 ft. (106 m). The coverage of the MEGA DI 1,200 kHz (1075 – 1150 kHz) beam is 75° and its max. depth range is approx. 125 ft. (38 m).
For Dual Spectrum CHIRP, this fish finder system offers three modes: Narrow, Wide, and Full. For these, the transducer uses conical beams. For the Narrow mode, the operating CHIRP range is 180-240 kHz, while its coverage is 25°. For the Wide mode, the CHIRP range is 140-200 kHz while the beam coverage is 42°. The Full mode offers the possibility to adjust the CHIRP range, but its default range is set to 150-220 kHz while the transducer beam coverage for this mode is also 42°. The maximum depth range that can be achieved with the Dual Spectrum CHIRP sonar with this transducer is 1,200 ft. (365 m) when using the Wide mode.
Of course, since the unit supports 50 kHz, it can be paired with a 50 kHz transducer. At 50 kHz CHIRP, this Humminbird fish finder system should be able to scan depths up to 3,500 ft. (1,066 m)
The unit offers the full range of standard sonar features. The list includes Amplitude Scope, Fish ID+, SwitchFire, WhiteLine, Bottom Lock, Fish Alarm, Depth Alarm, Circular Flasher mode for ice fishing, and more. It also has Sonar Recording and a rewind feature for reviewing the recorded sonar history. However, it requires a blank microSD card to be inserted into the unit as base for the recording.
All the Humminbird G4N units offer a pretty impressive range of navigation features. This being said, the Humminbird HELIX 8 CHIRP MEGA DI GPS G4N is equipped with an internal GPS receiver. It offers the possibility to select between 5 Hz and 10 Hz for five position updates per second or ten position updates per second. It has a GPS speed function (it can calculate the speed of your vessel based on the GPS input), and supports WAAS, EGNOS, and MSAS for position enhancement. The unit also has track recording, waypoint, and route creation functions.
Similar to most other Humminbird chartplotters, the HELIX 8 CHIRP MEGA DI GPS G4N comes pre-loaded with the standard Humminbird Basemap platform. These charts cover more than 10,000 U.S. lakes and also offer coastal U.S. coverage. They offers a fairly decent amount of information including day markers, depth markers, hazards, marinas, buoys, depth contours, and more.
Of course, the unit also supports premium charts from Navionics and LakeMaster. Its compatibility list includes Navionics Gold & HotMaps, Navionics+, Navionics Platinum+, LakeMaster, LakeMaster Plus, CoastMaster, as well as SmartStrike fishing charts. Plus, it can also use the SonarChart application available with some of the Navionics charts, for bathymetric mapping.
Speaking of bathymetric mapping, the unit also has its own built-in application for that – the AutoChart Live feature. This application uses the standard 2D CHIRP sonar and GPS data to reveal and record the depth contours of the lake that you’re scanning on the map. This being said, if the unit’s current maps don’t cover your favorite lake with satisfying depth detail, you can always create your own custom fishing map for it.
Like all the other G3N and G4N models, this Humminbird fish finder and chartplotter combo offers superior networking possibilities. Therefore, not only that it supports external GPS, or AIS, you can also upgrade to add-on technologies like Minn Kota i-Pilot Link, Talon and Raptor shallow water anchors, and even Humminbird CHIRP Radar.
Control unit features
The HELIX 8 CHIRP MEGA DI GPS G4N is an 8-inch display unit, featuring a color LCD display with LED backlight and a pixel matrix of 1024 x 600. It is IPX7 waterproof and should be able to withstand incidental water exposure with no problem. It does not have touchscreen technology, so the navigation through its menus and usage of its built-in application can only be done from the side keypad.
The unit is equipped with a dual microSD card unit. This can be a plus as you can use two cards at once, for example, one with Navionics charts and another one blank for data backup or data transfer, so you won’t have to swap cards all the time.
The unit offers superior wireless connectivity. It has both Wi-Fi and Bluetooth. Thus, you can sync it with your smartphone via the FishSmart app for map downloads or software updates. You can also control Talon and Raptor anchors from your chartplotter, as well as Cannon Optimum downriggers. Also, you can pair it with a RC2 remote control for wireless usage.
Along with the wireless connectivity, the unit also offers multiple networking possibilities. It has built-in NMEA 2000 and Ethernet. Therefore, you can easily connect it to an already existent boat network or connect other boating instruments to it. It supports Humminbird Radar, i-Pilot Link, external GPS, and AIS. Also, all the HELIX G4N models have actually been designed to work seamlessly with the One-Boat Network.
- Dual Spectrum CHIRP sonar;
- MEGA Down Imaging sonar;
- XNT 9 HW MDI 75 T transducer included;
- Depth capability up to 1,200 ft with the included transducer;
- Supports 50 kHz;
- Multiple sonar functions available, such as A-Scope, Bottom Lock, WhiteLine, Fish ID+, Alarms, SwitchFire etc;
- Sonar Recording and Screen Snapshot functions;
- 10 Hz internal GPS;
- Humminbird Basemap chart platform built-in;
- AutoChart Live included;
- Supports Navionics+, Navionics Platinum+, LakeMaster Plus, CoastMaster, and SmartStrike charts;
- Trackplotting, routes and waypoints functions;
- Large display with a resolution of 1024 x 600 for crisp imaging;
- IPX7 waterproof;
- Built-in NMEA 2000 and Ethernet;
- Wi-Fi and Bluetooth connectivity;
- Compatible with the FishSmart App and the RC Bluetooth remote controls;
- Supports Radar, I-Pilot Link, Talon and Raptor anchors, Cannon Downriggers, and One-Boat Networks;
- Supports AIS and GPS heading sensors;
- Dual microSD card reader;
- Upgradeable internal software;
- Gimbal mount included;
- Fairly easy to install.
- In-dash mount is not included;
- Unit cover is not included;
- Remote control is not included.
The Humminbird HELIX 8 CHIRP MEGA DI GPS G4N is a fish finder and chartplotter featuring Dual Spectrum CHIRP sonar, MEGA Down Imaging sonar, GPS, Humminbird Basemaps, AutoChart Live, superior networking features such as Ethernet and NMEA 2000, as well as wireless connectivity (Bluetooth and Wi-Fi). It also includes the XNT 9 HW MDI 75 T for both 2D and DI sonar. It’s a pretty complete unit, great for a wide range of boats, for both off-shore and inland fishing.