Choosing the right GARMIN Transducer

Garmin Transducer – Specs & Listings

To start, lets make sure we know what unit we are buying a transducer to pair with, and what type of sonar technology we plan to use. Match the unit with the transducer and the technology. Here’s a quick look at some of the different types of current sounder technology and types of transducers available.

CHIRP SONAR TECHNOLOGY – is one of the most sophisticated sonar technologies available for fishing and boating today. It truly provides amazingly clear target separation and definition because it puts even more energy onto a target than traditional sonar.

STANDARD SONAR – sends one single frequency at a time. Since the only feedback is from this one single frequency, there is limited information to work with, restricting the clarity and resolution available with standard sonar. 

 GARMIN CHIRP SONAR – Instead of sending just one single frequency, Garmin CHIRP sonar sends a continuous sweep of frequencies within a range from low to high and then interprets each frequency individulally upon its return.

Since this continuous sweep of frequencies provides a much wider range of information, Garmin CHIRP sonar is able to create a much clearer, higher resolution image with greater target separation and crisper fish arches.

For example, 80-160kHz is sweeping through the range from 80kHz all the way up to 160kHz and hitting every single frequency in between.

CHIRP TRANSDUCER – Picking the right transducer is very important to get the most Garmin CHIRP sonar. These transducers have elements that are tuned to specific frequency ranges and limit interference while transmitting and receiving data.

Choose the right frequency range for the water conditions you boat or fish in. Higher frequencies use a narrow beam widths, and are better for high-speed operation and rough sea conditions. Bottom definition and thermocline definition can be better when using a higher frequency. 

Lower frequencies use wider beam widths, which can let the fisherman see more targets, but could also generate more surface noise and reduce bottom signal continuity during rough sea conditions. Wider beam widths generate larger arches for fish target returns, making them ideal for locating fish. 

Wider beam widths also perform better in deep water, because the lower frequency has better deep water penetration. 

CLEARVÜ / SIDEVÜ SCANNING SONAR – ClearVü scanning sonar gives you an ultra clear sonar picture of objects, structure and fish that pass around your boat while SideVü scanning sonar shows fish and structure that is off to the sides of your boat.

ClearVü/SideVü scanning sonar with CHIRP technology is also available for some compatible chartplotter/sonar combos.  

 TYPES OF MOUNTS

In Hull – An in-hull transducer is installed inside a boat hull against the bottom and sends its signal through the hull.

PROS

• No need to drill through the vessel, no drag.
• Boat can be trailered without damaging transducer
• No exposure to marine growth
• Can be installed and serviced with vessel in water
• Gives great high-speed performance as long as water flow below the transducer is “clean” (no turbulence)
• Works with any engine type: inboard, outboard, and I/O when installed over solid fiberglass
• Performs well on both power and sailboats

CONS

• Not recommended for metal, wood, and cored fiberglass hulls
• Lose signal by transmitting through hull
• Hulls thicker than 3/4″ & epoxy laminates also cause signal loss

Kayak In-Hull – This mount attaches to the inside of a Kayak, against the bottom and sends its signal though the hull.

PROS

• No need to drill into the vessel
• No drag, protects transducer from rocks when launching
• Will not catch on weeds or marine vegetation
• Easily remove the transducer

CONS

• Not recommended for metal or wooden vessels
• Slight loss of signal by transmitting through hull
• Recommends flat section for best sealing against boat

Trolling Motor – Attaches either to the shaft or below the body of a trolling motor.

PROS

• Provides sonar images from the bow, right below where you are fishing, instead of further astern on the hull or at the transom
• Easy to install and remove, no need to drill into hull
• Stores with trolling motor when lifted out of water

CONS

• Sonar image corresponds to position of trolling motor, may not be optimum direction in currents or windy conditions
• Hangs low in the water, if you don’t pay attention to depth, it’s vulnerable to hitting submerged objects

Thru-Hull : Thru-hull transducers, as their name implies, are installed in a hole drilled thru the hull.

PROS

• Works with any engine type: inboard, outboard, or I/O, twins or single
• Works for power and sailboats alike
• Thru-hull transducers can be found for every hull material

“Flush” –  thru-hull transducers sit flush or nearly flush with the hull. Recommended for smaller boats with a minimum deadrise angle. They are often installed on sailing vessels because they produce minimal drag.

“External” – thru-hull transducers extend beyond the hull’s surface and usually require a fairing to aim the sound beam vertically. These are designed

for larger untrailered vessels. Installed with a High-Performance Fairing, the transducer face is flush with the surface of the fairing and parallel to the

waterline, resulting in a truly vertical beam, putting maximum energy on the target.

These are mounted in “clean water” forward of the propellers and running gear and  produces the most effective signal return, since nothing on the vessel interferes with the transducer’s active face.

When to Use a Thru-Hull Pair –  A Thru-Hull pair is recommended when mounting a SideVu transducer in a location that has a dead-rise greater than 5 degrees.

Garmin Transducer Specs & Compatibility