Transducers & Sounder Modules

Transducers and Sounder Modules Resources and Information

A sounder is a type of navigation unit that uses sonar technology to find the depth of a body of water or to visualize and locate underwater objects. Sounders are essential to the function of fishfinders and chartplotters. Transducers work in conjunction with sounder modules. They send out and receive ultrasonic signals to gather important data like depth and structure. This data is then transmitted to a display to assist the boat operator with navigation. 

Looking for more marine products? Check out our selection of Boat Accessories, Parts, and Products, or Boating Electronics and Navigation. Or browse transducers and sounder modules by category, including: 

• Garmin Transducers
• Humminbird Transducers
• Lowrance Transducers
• Raymarine Transducers
• Transducer Accessories

Transducers and Sounder Modules FAQs

What is a marine transducer? 

In simple terms, a transducer receives a signal of type, and converts it into a different type of signal. Marine transducers typically transmit and receive ultrasonic signals. These signals find the depth of a body of water and the shape of underwater structures, locate fish, and more. Upon receiving the return ultrasonic signal, the transducer converts the information into electrical pulses it then transmits to an electronic display to assist with navigation or fish location. 

What is a marine sounder module? 

A marine sounder works in conjunction with a transducer to send ultrasonic signals through the water. The sounder module keeps track of how many sound pulses are sent out in a given period of time and how quickly they’re returned. This information allows the sounder module to determine the distance soundwaves travel, thereby gauging depth. It can also use this same method to determine the shape of an object of geographic structure under the water. 

What does a chartplotter do? 

The chartplotter’s job is to show you where you are in the water and to help you navigate to where you are going. That sounds a lot like the GPS in your car, right? Yes and no.

While the chartplotter is run by a GPS similar to what is used within on-land devices, there are additional factors at play on the water, so the functionality and ability to process large volumes of complex data is vital. If the size and structure of the body of water you’re navigating is small and uncomplicated, you can simply type in a destination and a route will be generated for you to follow. However, on larger bodies of water with more complexity, you will likely need to enter waypoints and build a custom route.

Like the GPS in your car, a chartplotter uses GPS or GNSS data to measure bearing, speed, and direction to successfully navigate your route. However, the chartplotter begins to differ from the GPS in your car as you start considering its tracking and route navigation capabilities. A critical element that you must navigate while in the water is the underwater structures that can obstruct your route.

Structures like reefs, sandbanks, wreck sites, and other hazards must be avoided. A chartplotter’s ability to generate detailed electronic charts is another area in which this device differentiates itself from other navigational tools. A marine chartplotter will produce two types of charts: a raster chart, which is basically a scanned version of a paper chart; and a vector chart, which is composed of lines, points, and polygons using information pulled from a database. Vector charts are more dynamic, use less memory, and are more user-friendly than raster charts. In addition to being powerful navigational tools, many of these devices include fish finder functionality that detects sound waves underwater and uses the signals to project an image onto the screen to enable anglers to spot schools of fish in the depths.

How do I select the best chartplotter for my boat?

Offshore boating in the ocean or on the Great Lakes demands a higher functioning chartplotter. As mentioned above, if you primarily boat in small, inland areas, a basic chartplotter will likely serve you well. If your boat offshore, you will need to select a unit with greater processing speeds, the ability to easily download updated charts, and the capability to integrate with other tools and systems within your boat.

Generally speaking, smaller screens work well in smaller boats. Similarly, operators of larger boats will likely need a considerably larger screen since they will probably be situated at a greater distance from the chartplotter given the need to manage multiple interfaces.

Most chartplotters can be bracket mounted, which gives you a lot of flexibility. But be sure that the unit you select can be mounted so that it is visible from appropriate angles and can be protected from water—both waves and weather.

Chartplotters vary tremendously in price, from $150 to thousands of dollars. The type of boating you do and the bodies of water you boat on will determine what kind of chartplotter you need (what you want is another question). If you boat on fairly small inland lakes, a chartplotter robust enough for a transatlantic crossing is simply not necessary. However, if you will be boating on large bodies of water, you will need to spend more to ensure you have an instrument powerful enough to facilitate safe boating and ease of navigation.

Whether you select a fairly inexpensive chartplotter or a very expensive unit with all the bells and whistles, make sure that the unit is easy to operate and understand. The following is a selection of chartplotters that are popular among the PartsVu community. Given the diversity within the PartsVu community—from offshore boaters to fishermen who frequent smaller inland lakes—there is a significant diversity of needs. This range is represented within the units featured.

Why should I get a marine GPS unit?

A GPS navigation unit is a necessary addition to any boat. It will get you home should you lose your way exploring unknown waters, traveling many miles offshore, or boating at night. It can also be used to mark the last known position of a crewmember should they fall overboard. This can be a critical tool in case of an emergency scenario. Overall, a GPS unit comes in very handy in the following areas:

• Lakes/Rivers – fishing hollows, water ski spots, campsite locations, swimming holes/coves, meet up points
• Near Shore/In Shore – mark routes, weight points, barrier island spots, shelling locations, dockside restaurants, nearby coastal areas

What are the most popular Hummingbird GPS systems?

This five-inch, color screen GPS unit features high sensitivity down-imaging sonar, giving you a fish-eye’s view of everything that’s happening under your boat.

With a max depth of 600 feet below your boat, you’ll be able to make the most of your fishing trip. The HELIX 5 CHIRP DI GPS G2 has a range of features, including SmartStrike– a feature that takes you straight to the action by showing you where the fish are biting at any given moment. The patent pending AutoChart Live allows you to create digital, detailed maps live and on the water, or enhance existing maps in the system. Illuminated by its high definition display, your maps will look better than ever. 

These features are practically unbeatable at this price point, making the Humminbird HELIX 5 CHIRP DI GPS G2 a great choice for any angler.

This GPS unit features a larger 7” display and many of the features you’d expect from Humminbird: MEGA Side Imaging, providing crystal-clear viewing out to 125 feet on either side of your boat; Dual Spectrum CHIRP; SwitchFire Sonar, which allows the user to add or remove detail, account for water depth, temperature, turbulence, and more; Bluetooth capabilities; and more. 

One of the benefits of a larger, ultra-wide display screen is the option to choose between pre-loaded split screen options. The 480×800 screen provides a fantastic display, so you can use the Humminbird Basemaps with spectacular clarity.

When it comes to robust features and popularity amongst the PartsVu community, the SOLIX 10 CHIRP MEGA SI Fishfinder/GPS Combo G2 has both. Its features build on those of the previously mentioned HELIX 7 CHIRP MEGA SI GPS, including more powerful MEGA Side Imaging up to 200 feet. 

Some of the added notable features include Cross Touch Interface, which allows you to control your fish finder using the touchscreen or the keypad. Cross Touch lets you quickly and intuitively access technologies on your terms, no matter your situation and conditions. With added NMEA 2000® Networking capabilities, the SOLIX 10 CHIRP MEGA SI Fishfinder/GPS Combo G2 is practical, easy to use, and fully designed with the user in mind. While the price is steeper than some may prefer, it’s well worth every penny.