March 27, 2023 - Everett, WA- Forward Looking Sonar (FLS)

March 27, 2023

I took advantage of the haul-out to replace the anchor chain to also install a Forward Looking Sonar (FLS), a Garmin Panoptix PS-51 thru-hull transducer.

We spent time finding the appropriate location based on the dead rise angle of the exterior hull and accessibility from inside. Since the hull is 3/4" thick the angle had to be less than 20 degrees to accommodate the thru-hull fitting and transducer. A location on the port and starboard side was identified, at the same station, 27 feet aft of the boulbous bow, which will needed to be factored into interpretation of the readings. The starboard side was selected as this offered the best interior position and was well clear of any other transducers.

FLS located 27' aft of the tip of the boulbous bow

A 1/8" pilot hole was drilled from the inside-out to validate the location. Since all the house batteries are located on the port side, a location was found on the starboard side that would have been under house batteries, to locate the FLS. This had the additional benefit of providing protection of the FLS from incidental damage as it would reside in an enclosure.

Once the pilot hole location was validated a vertical 3/4" hole was back drilled from the exterior. Alignment was maintained by sighting the drill in two directions. The surface was sanded to remove paint, exposing the barrier coat. After cleaning the surfaces, the cut fairing block (matching the dead rise), and the thru-hull assembly, were installed with sealant and tightened. As the sealant squeezed out, the thru-hull nut was continually tightened to ensure a tight fit.

After removing the excess sealant the transducer was installed and verified that there was proper fit. And the exposed barrier coat and fairing block surfaces were touched up with bottom paint.

Final installation required routing the wiring to the Garmin displays as well as to the power source.