Transducer Installation Guide


The position of your Transducer is important for you to get the best reading.


Three types of Transducer are available include Bronze (made for timber and fibreglass hulls), Plastic (made for fibreglass, steel or alloy hulls) and Stainless Steel (made for steel or alloy hulls). Internally, the units are typically filled with urethane filler.


The boat's Hull construction and length will determine whether you need a Transom Mount, Thru-Hull, In-Hull, Pod or Pocket/Keel Transducer.



Transom Mount Transducers

When mounting on the Transom, be sure to use a straight edge to locate the Transducer so that it sits slightly lower than the Hull. Fix the mounts so that the screws are midway in the slots (as shown in images on the right). Look for an area of least turbulance when >Underway. Note: Don't mount behind any Planing straices or Scuppers that may be on your Hull. Popular Transom Mount Transducers include the Airmar P66 and TM260.


Finding Faults in Transom Mount Transducers

  • 1. If experiencing interference with a Transom mounted Transducer, you must test drive the vessel to determine what speed the image is lost at.
  • 2. Move the Transducer to its lowest position and retest. If screen image is improved repeat until you are satisfied with results.
  • 3. If screen image gets worse, move Transducer up and re‐test until improvement  is seen.
  • 4. Perform a slow but constant turn to the side of the Hull that the  Transom Transducer is mounted. Gradually increase Rate of Turn. If screen image improves the Transducer needs to be mounted lower in the water.
  • 5. If screen image is worse when turning to the same side as the Transducer try turning the opposite direction. This would indicate the Transducer needs to be mounted higher in the water.



Thru-Hull Transducers are enhanced by the use of a Fairing Block. This keeps the Transducer face parallel with the seafloor and improves high speed operation by creating a smooth water flow around the Transducer. These generally give better readings at speed and in a >Following Sea. Popular models include the B60 and B164.




Also a Thru-Hull Transducer can come with a tilted element for flush mounting on a Deep V Hull without the need of a Fairing Block. The tilt element allows the internal ceramic to be tilted for flush mounting. tilt element Transducers can allow a smaller trailer Boat to use higher quality transducers, with the lower acoustic Noise benefits of a Thru-Hull mounting over Transom mounting installation.




The Keel arrow needs to point at the Keel and not in the direction that the Keel runs.


 Points to be aware of with Thru-Hull mounting are:

  • 1. Cored hulls are important to seal the exposed core and provide sufficient support for the Transducer Hull nut to clamp against.
  • 2. Always check for Hull openings or projections in front of the mounting location. It's very difficult to move a Thru-Hull Transducer once it has been fitted.
  • 3. Don't mount Transducers in areas prone to Noise or vibration.
  • 4. Be aware of Hull lifting points or roller points if a vessel is trailered.



In-Hull Transducers should be contained in a tank cut to match the Deadrise of the vessel, which is filled with Propylene Glycol (marine antifreeze). The tanks should then be bonded to the Hull using fibreglass Resin. Popular models include the P79 and M260.




In-hull Transducers must also be fitted in location before fixing the tank. To find the best place to put it you can use one of three methods:

  • flood the Bilge area
  • put the Transducer into the bag and fill it with water
  • Use a water based lubricant to temporarily 'stick' the Transducer in place



Pod Transducers are designed to be fitted on Trolling motors, they attach via a large clamp assembly to the motor housing. It is important that enough free cable is left at the top of the motor to ensure it can turn freely.





Pocket or Keel Transducers are normally only used on commercial vessels. These Transducers have a housing that is designed to flush mount in an external Hull blister or directly in the Keel. We recommend that these are mounted towards the front of the Boat around the second Bow wave.





Some brands such as Humminbird have a 3 in 1 Transducer however Lowrance/Simrad have a separate Sideimage/Downimage Transducer. This is used on all NSS and HDS series. Available in Transom Thru-Hull in plastic or bronze. LSS-2 StructureScan Transducer specifically needs to be parallel with the Waterline when the vessel is at optimum speed. Transducer should be within 300mm of the Echosounder (if used) and at the same point Fore/Aft to ensure that structure overlay is accurate. StructureScan Transducers should be on the inboard side of the Echosounder Transducer to avoid obstruction of the Beam.

echosounderTransducer Angle


Mounting your Transducer:

  • 1. Mount on the Southboard side of the vessel if the prop is clockwise turning (95%) this means that water is flowing over the top of the Transducer.
  • 2. Never mount inline with a Hull projection like a water intake.
  • 3. Have a small amount of kickdown on the Transducer, around 2-5 degrees is good (as seen in the images on the right). This ensures a clean flow of water hits the Transducer face.
  • 4. Before mounting, take the Boat for a run and look for a smooth flow area at the Transom of the Boat.
  • 5. Remember to account for trailer rollers or lifting points when mounting Thru-Hull transducers.
  • 6. For stepped hulls, the Transducer needs to be mounted on the first Step and have enough room to kick up if struck.

Mounting your Trandsucer



Adjust the transducer so that it has around a 3-5 degree tail low tilt

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