Garmin GSD 26 Installation Instruction

To obtain the best performance and to avoid damage to your 

boat, install the device according to these instructions.
Read all installation instructions before proceeding with the 

installation. If you experience difficulty during the installation, 

contact Garmin Product Support.

Help us better support you by completing our online registration 

today.
• Go to 

.

• Keep the original sales receipt, or a photocopy, in a safe 

place.

The device may contain a software-update memory card. If so, 

follow the instructions provided with the card. If a software 

update memory card is not included, you must copy the 

software update to a memory card.

Insert a memory card into the card slot on the computer.

Go to 

Select Download next to “Garmin Marine Network with SD 

card.”

Read and agree to the terms.

Select Download.

Select Run.

Select the drive associated with the memory card, and select 

Next > Finish.

Before you can update the software, you must obtain a 

software-update memory card or load the latest software onto a 

memory card.

Turn on the chartplotter.

After the home screen appears, insert the memory card into 

the card slot.
NOTE: In order for the software update instructions to 

appear, the device must be fully booted before the card is 

inserted.

Follow the on-screen instructions.

Wait several minutes while the software update process 

completes.
The device returns to normal operation after the software 

update process is complete.

Remove the memory card.
NOTE: If the memory card is removed before the device 

restarts fully, the software update is not complete.

• Go to 

for in-country support information.

• In the USA, call (913) 397.8200 or (800) 800.1020.
• In the UK, call 0808 2380000.
• In Europe, call +44 (0) 870.8501241.

See the Important Safety and Product Information guide in the 

product box for product warnings and other important 

information.
You are responsible for the safe and prudent operation of your 

vessel. Sonar is a tool that enhances your awareness of the 

water beneath your boat. It does not relieve you of the 

responsibility of observing the water around your boat as you 

navigate.

Failure to install and maintain this equipment in accordance with 

these instructions could result in damage or injury.
Always wear safety goggles, ear protection, and a dust mask 

when drilling, cutting, or sanding.

When drilling or cutting, always check what is on the opposite 

side of the surface.
This equipment must be installed by a qualified marine installer.

A transducer is required to send and receive a sonar signal from 

the sounder. Proper transducer selection and installation are 

critical to the operation of the device. Because mounting 

locations vary, see your local Garmin dealer or contact Garmin 

 to select a transducer.

This device must be installed according to these instructions to 

get the best possible performance. If you experience difficulty 

with the installation, contact Garmin Product Support.

Because every boat is different, you must carefully plan the 

GSD 26 sounder installation.

Select a mounting location.

Mount the sounder.

Connect the sounder to the Garmin Marine Network and to 

power.

Connect the sounder to the transducer.

• Drill
• #8 (5 mm) drill bit for mounting surface
• 1 

1

/

4

 in. (32 mm) paddle drill bit or hole saw for mounting 

surface

• #2 Phillips screwdriver
• 3 mm flat screwdriver
• Cable ties (optional)
• Wire cutter
• Wire stripper
• 1 in. (24 mm) and 

19

/

32

 in. (15 mm) wrenches

• Marine sealant (optional)

• The sounder must be mounted in a location where it cannot 

be submerged.

August 2014

Printed in Taiwan

190-01821-02_0A