Garmin Signal™ VHF 400

The Garmin Signal™ VHF 400 is a compact, fixed-mount VHF radio designed for recreational and professional mariners. Featuring integrated GPS and AIS transponding capabilities, it delivers reliable two-way communication with exceptional clarity in coastal and offshore waters. Built with a rugged, waterproof design, this radio withstands harsh marine environments whilst maintaining consistent performance. The intuitive interface allows quick access to essential functions, including distress calling, weather alerts, and vessel tracking. With dual-watch capability and programmable channels, you can monitor multiple frequencies simultaneously. The integrated speaker and microphone system ensures clear communication even in challenging conditions. Perfect for cruising, fishing, or commercial operations where dependable VHF connectivity is essential. Quickly transmit a distress signal to nearby vessels with the distress button, which uses Class D DSC to automatically send crucial information that can help emergency responders. You can also use the intuitive DSC features to quickly initiate contact with other AIS-equipped vessels - simply select the vessel on the AIS plotter view, and call them with a tap of a button. Configure the radio, program the MMSI number, and get over-the-air software updates with the Active Captain App via built-in Wi‑Fi® connectivity. Installation is simple since VHF/DSC/AIS features only require a single VHF antenna and the GPS antenna/receiver is built into the unit. Chartplotter integration is seamless via the NMEA 2000® network and Garmin BlueNet™ Network. AIS TRANSPONDER Maintain situational awareness with the built-in Class B AIS SOTDMA transponder FIST MIC The included fist mic features a built-in speaker (5-watt RMS) and can be mounted in a different location to the head unit. RUGGED DESIGN The radio is built to withstand harsh marine environments with an IPX7 rating. EXTERNAL SPEAKER SUPPORT Connect a compatible external speaker for more playback options beyond the built-in speaker on the fist mic. HAILER WITH LISTEN BACK Connect the radio to a compatible loudhailer for broadcasting announcements. The listen back feature gathers background sounds that can be heard through the fist mic or external speaker. ADAPTIVE NOISE CANCELLATION Advanced noise cancellation uses machine learning algorithms to eliminate wind, wave and engine noise for our cleanest audio experience. AUTOMATED SQUELCH Radio activity is constantly monitored to eliminate unnecessary noise and static. You also have the option for manual fine-tuning. ADVANCED WATCH MODES All VHF channels are continuously scanned for activity in the background, allowing you to maintain watch over channel 16 and all your favourite preset channels simultaneously. VHF AUDIO PLAYBACK Didn’t catch that message? Replay it with VHF audio playback, and listen to audio messages for up to 3 minutes on any channel. Unit size Head Unit: 75 x 160 x 104 mm (3″ x 6.3″ x 4.1″) Fist Mic: 100 x 60 x 31 mm (3.9″ x 2.4″ x 1.2″) Weight Head Unit: 655 g (1.45 lbs) Fist Mic: 245 g (0.54 lbs) Operating voltage 9.6 - 32 VDC Water rating IPX7 Display Type Colour IPS LCD, capacitive touch Display Size 3.5″ (89 mm) Display Resolution 640 x 480 pixels Operating temperature –20° to 55° C (–4° to 131° F) Inland waterways (ATIS) Backlight 1,000 nits Multi-language interface VHF Features Adaptive noise cancellation Audio record and playback Auto squelch Dual/Tri watch Presets watch NOAA weather alert NOAA weather watch Loud hailer Loud Hailer listen-back Intercom support AIS target display AIS collision and MOB alarms Integrated AIS transponder VHF Radio Region All U.S., Canadian and International marine channels; NOAA weather channels VHF frequency range Tx 156.025–162.025 MHz VHF frequency range Rx 156.025–163.275 MHz VHF transmit power (max) 25 W, 1 W (high, low) Transmitter frequency tolerance +/0.3 kHz Adjacent channel power More than 70 dB Spurious emissions Less than –80 dBc (at 25 W) Sensitivity (12 dB SINAD) -118 dBm (-11 dBu/0.28 uV) Adjacent channel selectivity 80 dB Spurious response More than 75 dB VHF intermodulation More than 75 dB Max antenna gain 6 dBi Class D DSC Class Class D Sensitivity (1% BER) -117 dBm (-10 dBu/0.32 uV) Adjacent channel selectivity 80 dB Spurious response More than 75 dB Intermodulation More than 75 dB AIS Transponder Features Remote station support RM 100 (x5) AIS Class SOTDMA Class B Long range position reports (Msg 27) Frequency range 156.025–162.025 MHz AIS power output 5 W AIS Sensitivity (20% PER) -115 dBm (-8 dBu/0.4 uV) Adjacent channel selectivity 80 dB Spurious response More than 75 dB Intermodulation More than 65 dB GNSS Integrated GNSS receiver Integrated GNSS antenna Constellations GPS, GLONASS, BeiDou, Galilleo Differential support SBAS, AIS Msg 17 Navigation rate 10 Hz Sensors NMEA 2000® compatible Battery voltage Audio Max speaker output power{} Fist Mic: 5 W RMS, < 1% THD Max external speaker output power 15 W RMS, < 1% THD, 4 Ω Max hailer loudspeaker output power 25 W RMS, < 1% THD, 4 Ω Tactical features Night vision mode Stealth mode Electrical features Typical current draw at 12 Vdc Head Unit: 700 mA, 6 A max Fist Mic: 90 mA, 0.9 A max Compass safe distance Head Unit: 70 cm (27.6″) Fist Mic: 15.8 cm (40″) Networking & Connections Garmin BlueNet™ Network GMN 1.0/2.0 Wireless Connectivity Access point for mobile phones, 802.11b/g/n, integrated antenna Wireless security WPA2 Personal External GNSS antenna connector SMA Ant connector SO-239 (50 Ω) Security Information Security updates until at least (YYYY-MM-DD) 2028-05-28 In The Box: Garmin Signal™ VHF 400 head unit Fist mic Sun cover Head unit power and external audio cable with fuse (2 m) Fist mic power cable with fuse (2 m) Drop cable for NMEA 2000® network (2 m) Mounting hardware Mounting template Documentation