Recommended locations for in-hull and thru-hull transducers

[Chuck - Raymarine - Moderator]

Recommended locations for in-hull and thru-hull transducers

It is recommended that the transducer's installation manual be the primary reference for transducers to be installed onboard one's boat. Transducer installation location is critical to maximizing the performance of a fishfinding device and preventing transducers from suffering the effects of an aerated flow of water across the face of the transducer. In-hull hand thru-hull transducers should be installed forward of any steps, thru-hulls, or other hull features which may cause the transducer to be exposed to an aerated flow of water:



From a performance standpoint, a properly installed thru-hull transducer will typically deliver the best fishfinder imagery. The diagram below identifies locations which would typically be recommended for in-hull and thru-hull transducer installations.



If possible, it is recommended that the intended installation location be tested prior to installation of the transducer. In choosing the transducer installation location, it is recommended that baseline performance of the fishfinder/transducer be established with the transducer suspended over the side of the vessel while the vessel is stationary and in water whose depth is approximately equal to the depth which will most commonly be fished, but not less than 30 feet deep. It is further recommended that the testing location feature fish attracting structure. A series of screen snapshots of the fishfinder screen should be taken as a baseline to later be compared to the sonar imaging produced with the transducer re-located in the proposed installation location(s).

One would then rest the transducer on a ZipLock bag which has been filled with water (purge all air) and has been temporarily placed on the inside of the hull in the area where the transducer's performance will be tested. The transducer's energy will be transmitted through the water bag, through the hull, and into the body of water. Imaging samples should be taken while the vessel is stationary, while trolling, while on plane, and at high speed to determine the best transducer location for your vessel. The transducer may then be installed per the transducer's installation instructions.

In order to perform the zip lock bag test,
- the hull must be less than 1" thick (5/8" for the P74 and P79) in the location where the transducer will be installed
- the hull cannot be constructed using coring materials (ex. balsa, foam, etc.)

RAYFAQ#