Marine Devices with a Chassis Ground Screw

Many Garmin marine devices have a chassis ground screw to help prevent electrical interference. A marine-grade copper solid or stranded wire should be connected at the chassis ground and taken to the water ground. Examples of “water ground” could be found in different circuitry, wires, and connections to different systems of the vessel.  Refer to the vessel's electrical distribution system to identify them or contact the vessel manufacturer. 1   Highly recommended for touchscreen devices.

Bonding a marine device (chartplotters, sounder modules, etc.) using the device's chassis ground provides some protection to the internal circuits and components from directly induced electrical currents. 

NOTE: Bonding a marine device using the chassis grounding point may not stop or prevent damage caused by a lightning strike.

Below is a list of the screw sizes, and corresponding units for each type and size of screw:

M3x0.5x4.0,PHP,SS/P,Nylon

• echoMAP 70 / 70s / 70dv

• ECHOMAP Ultra Series

• GPSMAP 7x1 / 7x1xs

• GPSMAP 7x2 / 9x2 (Plus)

• GPSMAP 10x2 / 12x2 (Plus)

• GPSMAP 74xx / 76xx

• GPSMAP 84xx / 86xx

M3x0.5x6.0,PHP,SS/P,Nylon

• GMM 150 / 170 / 190

• GPSMAP 8xxx

• GPSMAP 8500 / 8530

M4x0.7x5,PHP/S,SS/P

• STRIKER 7 / 9

• STRIKER Plus 7 / 9

• STRIKER Vivid 7 / 9

M3x0.5x8.0,PHP LW/W

• AIS 600

• VHF 100

• VHF 200

• VHF 300

• VHF 300 AIS

M3x0.5x10.0,PHP,SS/P,Nylon

• GSD 24

• GSD 26

M4x0.7x6,PHP,SS/P,w/Nylon

• GMR 424 / 426 xHD2

• GMR 624 / 626 xHD2

• GMR 1224 / 1226 xHD2

• GMR 2524 / 2526 xHD2

M4x0.7x8,PHP,SS/P,w/Nylon

• GMR Fantom pedestals

Terminal Ring, 18-14 AWG  #6 Solid or Stranded Copper Wire Panduit-2176

• LiveScope GLS 10

¹ On a marine vessel, the DC ground or electrical bond may also be referred to as a "water ground". Refer to the vessel's electrical distribution system to identify them.