Sonar Black Boxes and Transducers

Perhaps inspired by the spy gadgets created by “Q” in James Bond films, the term “black box” as it applies to boat sonar is an industry term for devices that contain the electronic components of a fishfinder but lack a screen. Instead, after processing data from a sonar transducer, the “black box” transmits the data to a compatible chartplotter or multi-function display where fish, bottom structure and other information can be viewed. West Marine offers black box sounders (aka sonar modules) from Garmin, Lowrance and Raymarine.

Sonar Module Functionality

Each manufacturer’s black box sonar module offers the same functionality as comparable stand-alone fishfinders. For example, Raymarine’s RVX1000 3D CHIRP Sonar Module offers all of the performance and features as their Axiom Pro. Features include RealVision 3D sonar technology, CHIRP Side and DownVision, plus high powered 1kW dual channel CHIRP sonar.

Sonar Module Transducers

As mentioned, black box sonar modules take information received from a sonar transducer, process it and pass it along to a compatible chartplotter or multi-function display. While some black box modules include a transducer, others do not. When selecting a transducer for a sonar module, it is important to choose a model that will support the capabilities of the sonar module itself. For example, when selecting a transducer for Raymarine’s RVX1000 3D CHIRP Sonar Module, we suggest you choose a transducer capable of supporting the full suite of AXIOM RealVision features offered by the module, which in this case are its 3D, CHIRP, DownView and SideView functions.

Other Types of Sonar Transducers

Apart from transducers designed for use with West Marine’s current offering of sonar modules (and similar stand-alone fishfinders), West Marine offers a wide variety of sonar transducers designed for use with older pre-CHIRP single-, dual- and tri-frequency fishfinders. Transducers are offered with a choice of beam widths and frequencies. Once you have located a transducer with the beam width (or widths) and frequency (or frequencies) you require, it is important to select a model with a connection interface the same as the fishfinder with which the transducer will be used. There are a wide variety of connection interfaces, including 4-pin, 5-pin and many others—so be sure to select a transducer with a connection interface that allows you to plug the transducer into your fishfinder.

Transducer Mounting Styles and Materials

You also need to select a transducer with a mounting style that is right for you and your boat. Transom-mount, thru-hull and trolling motor mounting styles are offered. Transducer materials include plastic, bronze and stainless steel.

Will the transducer require a fairing block?

Another consideration when selecting a transducer is whether or not you need a fairing block. Fairing blocks are sometimes required when installing a thru-hull transducer to compensate for the deadrise of the boat’s hull.

When selecting a transducer, follow the manufacturer’s recommendation.

When choosing a transducer for a sonar module or for a stand-alone fishfinder, our overall recommendation is to select from the list of available transducers found in the module’s or fishfinder’s owner’s manual or within our online product descriptions.