Garmin GSD™ 25 — Advanced Sonar Module

The Garmin GSD™ 25 fishfinder module integrates several advanced technologies for detailed underwater detection. It supports:

Traditional fishfinderCHIRP single-channel and dual-channelSideVü CHIRP technologyDownVü CHIRP technologyThese combined capabilities provide a complete view of the underwater environment, including structures and fish beneath and alongside the vessel.

The Garmin GSD™ 25 delivers an RMS transmission power of 1 kW. This power enables exceptional penetration and resolution for underwater detection.

For superior clarity and better target separation, the GSD™ 25 operates in CHIRP single-channel and dual-channel modes over a wide frequency range from 40 kHz to 250 kHz.

The SideVü and DownVü CHIRP technologies of the GSD™ 25 operate on the frequencies of 455/800 kHz and 260/455 kHz. They provide near-photographic images of structures and fish beneath and alongside the vessel.

Yes, the GSD™ 25 is housed in a fully sealed polycarbonate plastic enclosure. It complies with IEC 60529 IPX7 waterproofing standards, meaning it is resistant to temporary immersion.

The GSD™ 25 module measures 251 x 66 x 192 mm (9.9 x 2.6 x 7.6 inches) and weighs 771 g (1.7 lb).

The GSD™ 25 is designed to operate within an extended temperature range from -15°C to 70°C (5°F to 158°F).

The GSD™ 25 requires a power supply of 10 to 35 Vdc. Its maximum power consumption is 27 W.

The minimum safe distance from a magnetic compass for the GSD™ 25 is 30 cm (11.8 inches).

The GSD™ 25’s LEDs indicate its operating status:

Green (slow blinking): The depth sounder is connected to a chartplotter and operating correctly.

Red (slow blinking): The depth sounder is powered on but not connected or waiting to connect to a chartplotter.

Red/Green (slow blinking): The depth sounder is in test mode.

Red (fast blinking): Indicates a system error; the chartplotter will display a message.

Red (solid): Indicates a hardware failure in the depth sounder.

To install the GSD™ 25, you will need the following tools:

A drill and drill bitsA Phillips #2 screwdriverCable ties (optional)Marine sealant (optional)

When selecting a mounting location for the GSD™ 25, consider the following points:

The depth sounder must not be submerged.The location must provide adequate ventilation and not expose the device to extreme temperatures.The depth sounder's LEDs must be visible.The power and network cables must be easily connectable.The transducer cable must be connectable.

Yes, if you mount the bracket on fiberglass using screws, it is recommended to use a countersink drill bit to drill a pilot hole only through the top gelcoat layer. This helps prevent cracking of the gelcoat when tightening the screws. Additionally, Garmin recommends applying anti-seize lubricant on stainless steel screws before installation to prevent them from seizing.

To connect the GSD™ 25 to the Garmin marine network:

If your boat is equipped with a GMS™ 10 network port expander, connect the network cable to an available port on the GMS 10. If your boat is not equipped with a GMS™ 10 network port expander, connect the network cable directly to the network port of your chartplotter. Ensure the notches are properly aligned and the locking collars are tightened.

To connect the GSD™ 25 power cable:

Connect the stripped end of the power cable to a 12 Vdc power source and to ground. Align the notch at the end of the power cable with the device’s power port and insert the cable. Tighten the locking ring. Important: Do not remove the inline fuse holder. The correct fuse (4.0 A) must be in place to prevent risk of injury or damage to the product.

The general steps for installing the GSD™ 25 are as follows:

Select a suitable mounting location.Physically mount the depth sounder by marking pilot holes, drilling, and securing the unit.Connect the depth sounder to the Garmin marine network and the power supply.Connect the depth sounder to the transducer.It is important to carefully plan the installation and take necessary precautions, especially when drilling.

The Garmin GSD™ 25 is an advanced fishfinder solution designed for Garmin marine navigation systems. It connects via the Garmin marine network, typically to a compatible chartplotter for data display.

The GSD™ 25 is compatible with a variety of Garmin transducers supporting its different technologies and frequencies. It supports transducers for:

Traditional depth sounder (50/77/83 kHz)CHIRP single-channel and dual-channel (40 kHz to 250 kHz)SideVü and DownVü CHIRP (455/800 kHz and 260/455 kHz)The choice of transducer will depend on the frequencies and technologies you wish to use.