Garmin GPSMAP 78s Manual Download

The Garmin GPSMAP 78s is a rugged, waterproof handheld GPS device featuring a high-sensitivity GPS receiver, a 2.6-inch color TFT display, a built-in worldwide basemap with shaded relief, a 3-axis tilt-compensated electronic compass, a barometric altimeter, and support for BlueChart® g2 and LakeVü™ g2 mapping. It offers wireless sharing of waypoints, tracks, routes, and geocaches between compatible devices. Below are key sections for features, setup, operation, specifications, and troubleshooting.

Features at a Glance

Key components: High-sensitivity GPS receiver, 2.6" color TFT display, 3-axis electronic compass, barometric altimeter, microSD™ card slot, USB port, and wireless connectivity.

Feature	Description
High-sensitivity GPS	Accurate positioning even in heavy cover or deep canyons
2.6-inch color display	Sunlight-readable, 160 x 240 pixels
3-axis electronic compass	Shows heading while standing still (tilt-compensated)
Barometric altimeter	Tracks changes in pressure to plot elevation
Built-in worldwide basemap	Includes shaded relief for topographic context
Wireless connectivity	Share data wirelessly with compatible Garmin devices
MicroSD card slot	For loading additional maps (BlueChart®, Topo, etc.)
Waterproof rating	IPX7 standard (submersible to 1 meter for 30 minutes)
Battery life	Up to 20 hours (2 AA batteries)
Preloaded with marine aids	Includes coastal navigation markers

Getting Started

Unpack and inspect contents. Insert batteries and power on.

1. Install batteries: Open battery compartment, insert two AA batteries (NiMH or lithium recommended).
2. Initial power on: Press and hold POWER button. Follow on-screen prompts.
3. Acquire satellites: Go outdoors with clear view of sky. Device will automatically search for satellites.
4. Set preferences: Configure language, units, time format, and coordinate system in Setup menu.

WARNING! Use only recommended batteries. Do not mix old and new or different types of batteries.

Basic Operation

Learn the main buttons and interface navigation.

1. Page button: Cycles through main pages (Map, Compass, Altimeter, Main Menu).
2. Rocke r / ENTER: Moves cursor and selects highlighted items.
3. MENU button: Opens context-sensitive options for the current page.
4. POWER button: Turns device on/off; holds to adjust backlight.
5. ZOOM buttons: In/Out on Map page.
6. MARK button: Saves current location as a waypoint.
7. QUIT button: Returns to previous screen or cancels action.

Tip: Press and hold MENU from any page to access the Main Menu directly.

Specifications

• Display: 2.6-inch diagonal, 160 x 240 pixels, color TFT, sunlight readable.
• GPS Receiver: High-sensitivity, WAAS enabled, HotFix® satellite prediction.
• Memory: 1.7 GB internal, microSD card slot (supports up to 32 GB).
• Wireless: ANT+® technology for data sharing.
• Interface: USB 2.0 (for data transfer and power).
• Waterproof: IPX7 standard.
• Battery: 2 AA batteries (not included). Up to 20 hours typical use.
• Dimensions: 2.4" x 6.3" x 1.4" (6.1 x 16.0 x 3.6 cm).
• Weight: 7.6 oz (215 g) with batteries.
• Operating Temp: -4° to 140°F (-20° to 60°C).

Navigation & Mapping

Use the Map page as your primary navigation screen.

1. View Map: Press PAGE to select Map page. Use ZOOM to adjust detail.
2. Navigate to a Point: Use rocker to move cursor to location, press ENTER > 'Go'.
3. Follow a Route: Select MENU > Routes > Select Route > Navigate.
4. Add Maps: Install detailed maps via Garmin BaseCamp™ software on a computer and transfer via microSD card or USB.
5. Create Waypoints: Press MARK to save current location. Edit name/symbol as needed.

Note: The built-in basemap provides minimal detail. For detailed topography or marine charts, purchase and install additional maps.

Wireless Sharing

Share data wirelessly with other compatible Garmin devices (e.g., GPSMAP 78 series, Oregon® series).

1. Ensure both devices are powered on and within 3 meters (10 feet).
2. On your GPSMAP 78s, go to Main Menu > Wireless > Transfer.
3. Select type of data to send (Waypoints, Routes, Tracks, Geocaches®).
4. Select the item(s) to send, then choose 'Send'.
5. On the receiving device, accept the transfer.

Tip: Wireless transfer is one-way. You cannot edit data on the receiving device during transfer.

TracBack® & Routes

Use TracBack to reverse your track log and navigate back to your starting point.

1. Save Active Track: Go to Main Menu > Tracks > Setup > Log Track > Save.
2. Use TracBack: From the Map page, press MENU > TracBack. Select saved track.
3. Follow TracBack: Device will create a route using points from your saved track.
4. Create a Route: Main Menu > Routes > Create New. Add points from map or waypoint list.

WARNING! Always save your track log before using TracBack. Unsaved track logs are cleared on power off.

Compass & Altimeter

Calibrate the electronic compass and altimeter for accurate readings.

Calibrate Compass: 1. Go to Compass page. 2. Press MENU > Calibrate Compass. 3. Follow on-screen instructions (hold level and rotate slowly).

Calibrate Altimeter: 1. Go to Altimeter page. 2. Press MENU > Calibrate Altimeter. 3. Choose 'Auto Calibration' or manually enter known elevation/barometric pressure.

Note: The electronic compass must be calibrated whenever you change batteries or move significant distances. Keep device level while using compass.

Care & Maintenance

Clean with a soft, damp cloth. Do not use harsh chemicals or solvents.

Battery Care: Remove batteries if device will not be used for several months. Use NiMH or lithium batteries for best performance in cold weather.

CAUTION! Do not charge non-rechargeable batteries in the device. The USB port provides power but does not charge AA batteries.

Regulatory Information

This device complies with Part 15 of the FCC Rules. Operation is subject to the condition that this device does not cause harmful interference. This device meets the requirements of the Radio Equipment Directive 2014/53/EU. For detailed compliance information, see the regulatory appendix in the full manual. © 2010-2025 Garmin Ltd. or its subsidiaries. Garmin, GPSMAP, TracBack, BlueChart, and LakeVü are trademarks of Garmin Ltd. or its subsidiaries.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No power / Won't turn on	Dead batteries, incorrectly installed	Install fresh batteries; ensure correct polarity.
Poor GPS accuracy / No signal	Obstructed sky view, needs reset	Move to open area; from Map page, MENU > Satellite > 'Restart GPS'.
Compass inaccurate	Needs calibration, near metal/magnetism	Calibrate compass; move away from magnetic sources.
Device does not connect to computer	Faulty cable, wrong mode	Use provided USB cable; ensure device is in 'Mass Storage' mode (Setup > Interface).
Screen is dim or unreadable	Backlight setting low, battery save mode	Adjust backlight (hold POWER); disable battery save mode in Display settings.
Wireless transfer fails	Devices too far, not compatible	Bring devices within 3m; ensure both support ANT+ wireless transfer.

Reset: If device freezes, perform a soft reset by holding POWER + PAGE + BACK for 10 seconds (data will be preserved).

Support: For the latest software updates and full manual, visit support.garmin.com.