antenna should be installed to maintain a distance of 2.5 m (98.42 in.)determined using 25 W output to an omni-directional, 9 dBi gain antenna. TheGarmin declares a MPE radius of 2.5 m (98.42 in.) for this system, which wasVHF 315 SERIESInstallation InstructionsImportant Safety InformationWARNINGSee the Important Safety and Product Information guide in the product box forproduct warnings and other important information.CAUTIONAlways wear safety goggles, ear protection, and a dust mask when drilling,cutting, or sanding.NOTICEWhen drilling or cutting, always check what is on the opposite side of thesurface.Registering Your DeviceHelp us better support you by completing our online registration today. Keepthe original sales receipt, or a photocopy, in a safe place.1 Go to my.garmin.com.2 Sign in to your Garmin®account.Tools Needed• Pencil• Drill• 22 mm (7/8 in.) drill bit or hole saw• 3 mm (1/8 in.) drill bit• 13 mm (1/2 in.) drill bit• 4.76 mm (3/16 in.) wrench (for mounting the handset connector)• Additional drill bits appropriate for the surface and hardware• Phillips screwdriver• Rotary cutting tool or jigsaw (for mounting the active speaker)• Marine sealant (optional)Mounting ConsiderationsNOTICEThis device should be mounted in a location that is not exposed to extremetemperatures or conditions. The temperature range for this device is listed inthe product specifications. Extended exposure to temperatures exceeding thespecified temperature range, in storage or operating conditions, may causedevice failure. Extreme-temperature-induced damage and relatedconsequences are not covered by the warranty.• You must mount the device in a location where it will not be submerged.• You must mount the device in a location with adequate ventilation where itwill not be exposed to extreme temperatures.• If possible, you should mount the device horizontally, with the top of thedevice facing upward.• If you must mount the device vertically, you should orient it so theconnectors do not point upward. This helps avoid potential water retentionaround the connectors.Antenna Mounting and EME ExposureWARNINGRadio operators with cardiac pacemakers, life-support machines, or electricalmedical equipment should not be exposed to excessive radio-frequency (RF)fields, because the RF field may interfere with the function of their medicalequipment.CAUTIONThis device generates and radiates radio frequency (RF) electromagneticenergy (EME). Failure to observe these guidelines may expose people to RFradiation absorption exceeding the maximum permissible exposure (MPE).between the antenna and all people.Mounting the DeviceNOTICEIf you are mounting the device in fiberglass, when drilling the pilot holes, it isrecommended to use a countersink bit to drill a clearance counterbore throughonly the top gel-coat layer. This will help to avoid cracking in the gel-coat layerwhen the screws are tightened.Before you mount the device, you must select a mounting location anddetermine the mounting hardware needed for the surface.NOTE: Mounting hardware is included with the device, but it may not besuitable for the mounting surface.1 Place the device in the mounting location and mark the location of the pilotholes.2 Using a bit appropriate for the surface and the mounting hardware, drill apilot hole for one corner of the device.3 Loosely fasten the device to the surface with one corner and examine theother three pilot-hole marks.4 Mark new pilot-hole locations if necessary.5 Remove the device from the mounting surface.6 Drill the appropriate pilot holes for the other three marks.7 Secure the device to the mounting location.Active Speaker Mounting ConsiderationsNOTICEThis device should be mounted in a location that is not exposed to extremetemperatures or conditions. The temperature range for this device is listed inthe product specifications. Extended exposure to temperatures exceeding thespecified temperature range, in storage or operating conditions, may causedevice failure. Extreme-temperature-induced damage and relatedconsequences are not covered by the warranty.The included active speaker is optional, and is not required when installing theVHF 315 device. When selecting a mounting location for the active speaker,observe these considerations.• To avoid interference with a magnetic compass, do not install the activespeaker closer than 50 cm (19.6 in.) to a compass.• You must install the active speaker inline with a GHS™ 11 handset.• You must install the active speaker within 1.2 m (48 in.) of the location youwant to connect the GHS 11 handset.• You must install the active speaker connected to the primary handset(connected to the GHS 11 STATION 1 port) in the wheelhouse or anadjacent room, in accordance with FCC law.• You can use the included 10 m (32 ft.) extension cable to connect theactive speaker to the VHF radio. You must select a mounting location forthe speaker where you can connect the extension cable to the activespeaker and to the GHS 11 STATION 1 port on the VHF radio. If needed,additional extension cables are available from your Garmin dealer.Mounting the Active SpeakerNOTICEBe careful when cutting the hole to mount the speaker. There is only a smallamount of clearance between the case and the mounting holes, and cuttingthe hole too large could compromise the stability of the speaker after it ismounted.Before you can mount the speaker, you must select a mounting location.1 Trim the template and make sure it fits at the mounting location.2 Secure the template to the mounting surface.3 Using a 13 mm (1/2 in.) drill bit, drill a hole inside the corner of the line onthe template to prepare the mounting surface for cutting.2 Installation Instructions