Simrad SN90 Purse seine and trawling sonar

Determining the location the transducer

A single answer to the question “where to install the transducer” cannot be given.

The physical location of the transducer depends on the vessel's design and construction, how the hull is shaped, and how the water runs along the hull. There are however a number of important guidelines, and some of these are even conflicting.

The information here must be considered as general advice. Each transducer installation must be handled separately depending on the hull design.


Summary and general recommendations

Some of the installation guidelines provided may be conflicting. Each vessel must be treated individually in order to find the best compromise.

In general, the most important factor is to avoid air bubbles in front of the transducer face. For this reason, the recommended transducer location is normally in the fore part of the hull, well ahead of the noise created by the bow wave. The maximum distance from the bow is normally equal to one third of the total water line length of the hull.

If the vessel hull has a bulbous bow, this may well be a good transducer location, but also in this case the flow pattern of the aerated water must be taken into consideration. Often the foremost part of the bulb is preferable.

This applies to the vessel in normal trim and speed. Under no circumstances should the transducer be tilted backwards when the vessel is moving at an appreciable speed. Mounting screws must never be extruding from the transducer, and the space around the screws must be filled with a compound or a locking ring.

Copyright Kongsberg Maritime AS 2007