GT15M-TM Transducer - Rear Mount CHIRP Mid-Frequency

The Garmin GT15M-TM transducer is a versatile solution designed for freshwater anglers. It delivers targeted performance for fish identification and bottom mapping, focusing primarily on traditional sonar. It can be mounted on the transom or on an electric trolling motor.

The Garmin GT15M-TM transducer uses CHIRP mid-band technology. It operates in the 85 to 165 kHz frequency range, providing clear detection and sharp separation of underwater targets.

The GT15M-TM transducer has a transmit power of 600 W RMS (Root Mean Square), providing effective detection capability in freshwater environments.

The Garmin GT15M-TM transducer can reach a maximum depth of 1,900 feet (approximately 579 meters) in freshwater, providing extensive coverage for most lakes and rivers.

In addition to fish detection and bottom mapping, the GT15M-TM transducer provides accurate depth and water temperature readings. This data is essential for analyzing fishing grounds.

The GT15M-TM fishfinder is designed specifically for freshwater anglers who prioritize simplicity and performance in traditional 2D sonar. It provides a solid foundation for efficient navigation and fishing without excessive data.

The Garmin GT15M-TM transducer beam has a variable width of 24° to 13°. This feature improves bottom definition and provides clear separation of underwater targets.

The GT15M-TM transducer is compatible with Garmin units that support traditional sonar. On compatible Garmin units, it can also support ClearVü and SideVü technologies with a power output of 500 W.

Yes, the GT15M-TM transducer can support ClearVü and SideVü technologies, but only at 500 W power and on compatible Garmin units. Its primary function remains traditional sonar.

Yes, as a transom-mounted transducer, the GT15M-TM is compatible with all hull materials. It attaches to the outside of the boat's transom, making it versatile for various vessels.

The Garmin GT15M-TM transducer is designed to be mounted in two main ways:

On the boat's transom.On the electric trolling motor.These options provide flexibility for different boat types and fishing preferences.

For optimal performance, the depth sounder must be mounted:

Parallel to the waterline.As close as possible to the center of the boat.If the propeller rotates clockwise, mount it on the starboard (right) side. If it rotates counterclockwise, mount it on the port (left) side.Away from planking, stiffeners, fittings, water intakes or outlets, or anything that creates air bubbles or turbulence.At least 38 cm (15 inches) from the propeller on boats with outboard or inboard/outboard engines.

If your boat spends a lot of time in the water, you must prepare the transducer and mounting hardware:

Lightly sand the transducer and hardware with fine-grit abrasive pad.Clean the transducer and hardware with isopropyl alcohol.Apply water-based antifouling paint to the transducer and hardware to prevent marine growth.Warning: Never use acetone or acetone-based products, as this will damage the transducer’s plastic housing.

No, it is essential not to cut the Garmin GT15M-TM depth sounder cable. Cutting the cable will void the product warranty. You must route the cable while avoiding cuts and pinches.

To reduce interference with your depth sounder signal:

Route the depth sounder cable away from ignition wires, batteries, electric trolling motors, and high-energy wires (radar, audio amplifiers, autopilot pumps). Avoid mounting the transducer behind frames, struts, fittings, water intakes, or discharge outlets that create turbulence. If using multiple transducers, mount them at least 60 cm (24 inches) apart if they share the same frequency. Ensure proper grounding of the sonar unit and other equipment to reduce electromagnetic interference.

Yes, testing the installation is crucial:

Check for leaks around the screw holes added below the waterline.The transducer must be submerged to function properly and provide accurate depth or distance readings.Power on the display and take the boat out into open water to observe performance and make adjustments if necessary.

When routing the depth sounder cable:

Avoid running it near electrical wires or other sources of electrical interference. Ensure the cable is not pinched, especially if the transducer is mounted on an electric trolling motor that is deployed or stowed. If the cable must pass through the transom, use a cable gland and marine sealant to ensure watertightness. Never cut the cable, as this will void the warranty.

When adjusting the depth sounder depth on the transom, make adjustments in small increments. Placing the transducer too deep can negatively affect boat performance and risks damaging the transducer by striking underwater objects. The mounting bolt must be tight enough to hold the transducer at high speed, but loose enough to allow it to pivot if it encounters an obstacle.

Yes, using marine sealant is strongly recommended and necessary:

Apply marine sealant to the included screws when securing the depth sounder assembly to the transom. If you route the cable through the transom, fill the cable passage hole with marine sealant to fully cover the cable and ensure a watertight seal around the hole and the cable. Also apply marine sealant to the screws of the cable gland cover. This helps prevent water ingress into your boat.