Transducer performance is severly impacted by marine growth. Allowing these organisms to take over the wet part of a system only degrades the transmitted and received energy and further decouples the transducer from the water while underway.
This growth resulted in failure to detect anything in the water, and bottom returns to be faint.
It may seem obvious on it’s face, but on more than one occasion, marine growth has been the culprit in an underperforming system. After a client describes reduced sounder performance over time, the next question asked is, “when was the last haulout?”
The challenge with protecting transducers is to not damage the material that the device is made out of. Bottom paints have chemicals and compounds that can destroy transducers by effectively melting the materials. The general danger is with compounds known as ketones. The protective coatings made specifically for transducers are formulated not to do any damage to these plastics and epoxies used in the construction of transducers.
Six months of growth in the harbor; these transducers were not protected with anti-foul coating
The go-to solution for protecting transducers is to use a water based anti-foul coating from brands such as MDR, Pettit, Sea Hawk, or Woolsey. These products can be found at your local marine supply, along with a new product from the industry leading manufacturer of transducers, Airmar. This coating, dubbed Foul Free, leaves a durable, clear finish that seems to perform very well. It is also the only coating certified by Airmar to not degrade transducer performance.
Application of Foul Free is straight forward and quick, leaving a protective barrier and maintaining performance of the transducer for up to two years. Because this is a new product, I wanted some practical, real-world results before commenting on my experience with the performance of this new coating. The before image was after 6 months in the water without anti-foul coating, and the image below is after 3 months in the water with Foul Free coating by Propspeed.
Results from 3 months in the harbor with Foul Free coating applied.
Polar Marine Alaska recommends Foul Free for coating all transducers on vessels spending any amount of consecutive time in the water.
Capt. Brett