Garmin GT12M-THF Installation Instructions Manual Download Page 1

GT12M-THF/GT15M-THF TRANSDUCER

INSTALLATION INSTRUCTIONS

Important Safety Information

 WARNING

See the Important Safety and Product Information guide in the chartplotter, fishfinder, or sounder 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.

 CAUTION

For the best possible performance and to avoid potential injury, damage to the device, or damage to your vessel, 
installation by a qualified marine installer is recommended.
Failure to install and maintain this equipment in accordance with these instructions could result in damage or 
injury.
To avoid possible personal injury, always wear safety goggles, ear protection, and a dust mask when drilling, 
cutting, or sanding.

NOTICE

When drilling or cutting, always check what is on the opposite side of the surface to avoid damaging the vessel.
Read all installation instructions before proceeding with the installation. If you experience difficulty during the 
installation, contact Garmin

®

 Product Support.

To prevent interference and avoid possible overheating damage, do not install the transducer near the engine or 
in the engine room.
To prevent damage to the cable and the transducer, do not use the cable to pick up or pull the transducer.
Always operate the transducer when it is submerged. Operating the transducer when it is exposed to the air may 
result in damage due to overheating.
To prevent permanent damage to the surface of the transducer, do not use solvents such as mineral spirits, 
acetone, Methyl Ethyl Ketone (MEK), or similar products when cleaning. Do not use a power sander or pressure 
washer to clean the transducer.

GUID-FBCD49EF-8D56-47CE-97B4-1B8840440007 v1

July 2023

Summary of Contents for GT12M-THF

Page 1: ...s wear safety goggles ear protection and a dust mask when drilling cutting or sanding NOTICE When drilling or cutting always check what is on the opposite side of the surface to avoid damaging the ves...

Page 2: ...or composite hulled vessel You must not install this model in an aluminum or steel hull NOTICE Installing the GT12M THF transducer in an aluminum or steel hull will create galvanic corrosion that may...

Page 3: ...should be mounted approximately 1 3 aft of the waterline length of the vessel from the bow and from 150 to 300 mm from 6 to 12 in to the side of the centerline The transducer should be mounted parall...

Page 4: ...le at the installation location by measuring with a smartphone application an angle finder a protractor or a digital level You can also ask your boat manufacturer for the deadrise of a specific point...

Page 5: ...r hole completely through the hull 5 From inside of the hull use a slightly larger hole saw to cut only the inner fiberglass skin and core NOTICE Take care to cut only the inner fiberglass skin and co...

Page 6: ...ver the pilot hole and surrounding area outside the hull to reduce cracking of the gel coat 3 Use a utility knife to cut a hole in the tape over the pilot hole 4 From outside the hull use a 73 mm 2 7...

Page 7: ...hrough the mounting hole using a twisting motion to squeeze out excess sealant 3 From inside the hull place the nylon washer and hull nut onto the stem 4 From inside the hull rotate the transducer as...

Page 8: ...er and isolators Applying Marine Sealant to a Thru hull Transducer page 6 5 Insert the transducer through the mounting hole using a twisting motion to squeeze out excess sealant 6 From inside the hull...

Page 9: ...uitable fastening equipment to secure the cable where necessary to protect it from damage You should avoid over tightening zip ties and compressing the cable 2 Connect the transducer cable to the appr...

Page 10: ...ld detergent 2 If the fouling is severe use a non metallic scouring pad or putty knife to remove growth 3 Wipe the transducer dry Specifications All Models Specification Measurement Frequencies1 From...

Page 11: ...garmin com support warranty 68 02 2642 8999 02 2642 9199 2 SJ T11364 GB T26572 GB T26572 2023 Garmin Ltd or its subsidiaries Garmin and the Garmin logo are trademarks of Garmin Ltd or its subsidiarie...

Page 12: ...2023 Garmin Ltd or its subsidiaries support garmin com...

Reviews: