Overview

The Garmin 010-12390-20 is a 15 ft (4.5 m) HDMI cable for connecting a GPSMAP 8400 or 8600 series chartplotter to an HDMI video source or an external display. It supports Full HD video up to 1080p and uses a water-resistant connection that stays secure in a helm environment.

On compatible GPSMAP 8400/8600 units, HDMI video can be shown full-screen or in a split-screen layout alongside navigation and sonar views. Audio can ride with the HDMI feed for playback on the chartplotter, and feeding that audio into an onboard stereo setup typically calls for a separate NMEA audio connection.

This cable makes sense for boats that want a camera feed at the helm, a computer connected for planning and display, or a second screen where the operator can still see what is happening on the chartplotter.

Key features

• 15 ft (4.5 m) length for typical helm-to-console routing
• Fits GPSMAP 8400 and 8600 series chartplotters equipped with an HDMI connection
• Supports Full HD video up to 1080p for external video sources and compatible displays
• Water-resistant, secure chartplotter-side connection suited to marine installs
• Video viewing supports full-screen or split-screen layouts on compatible GPSMAP 8400/8600 units
• Touchscreen control of a connected computer requires a USB connection in addition to HDMI

Installation and setup

Plan the run like any other helm cable: keep it protected from chafe, avoid tight bends, and route it where vibration will not work the cable against sharp fiberglass edges or metal. Make the final connections in a dry area, then dress and secure the cable so the connector is not carrying strain.

If your installation needs more than 15 ft, extend the run with an active HDMI cable and an HDMI coupler rather than relying on a long passive extension. This helps maintain signal integrity when the cable has to travel through larger consoles or up to a remote monitor.

Compatibility and video integration

This is an HDMI accessory cable intended for GPSMAP 8400/8600 series chartplotters and other compatible Garmin marine displays that use the same HDMI connection. It can be used either to bring HDMI video into the chartplotter or to send the chartplotter video to a monitor or TV, depending on how your system is set up and what your display supports.

Common sources include onboard camera systems, media devices, and computers. Devices with DVI-D video output can be used with a standard DVI-to-HDMI adapter or cable when needed, and phones or tablets generally require an external adapter or dongle to provide HDMI.

Audio notes

HDMI carries both video and audio, but how that audio is handled on a boat depends on the rest of the system. If the goal is to hear the HDMI source through your boat stereo rather than on the chartplotter itself, plan on integrating audio through the appropriate NMEA audio connection and matching stereo inputs.

Use cases on board

For fishing boats, this cable is a clean way to bring a live camera view to the chartplotter while keeping charts visible on the same screen. On cruisers and larger center consoles, it is also useful when you want a second display at the helm or in the cockpit that mirrors what is shown on the chartplotter.