In-Hull transducer plus depth finder and plotter

[JMo]

Looking to replace the original Apelco 360 depth finder and Transducer. Has anyone installed a recent “In-Hull” transducer and Depth finder / GPS plotter ?

[Viper]

By "in-hull" are you talking about the design that mounts to the surface of the glass in the bilge and shoots through it rather than the type you drill a hole in the hull? What do you need to know?

If you're talking about the type that shoots through the hull, there are some pros and cons. The pro is that you can install it while in the water and you don't have to drill through the hull. The con is that the type of hull construction affects some of the efficiency. It will be more efficient shooting through solid glass rather than a cored hull. For this reason, some brands will recommend that you cut away the top layer of glass large enough to accommodate the unit, and remove the core so that you're gluing the unit to the bottom layer of glass. Some will recommend that you bed it in epoxy while others say 3M 5200 is fine around the perimeter. Then it's a matter of filling it with liquid as ducers must be in contact with a fluid or not have an air gap between it and fluid. Some recommend mineral oil and others propylene glycol antifreeze. Each brand will have a method of adjusting the angle of the element. The round units typically have a method by which you can compensate for the angle of the hull at the mounting location through angled housings and graduations on the top covers/caps.

The less complicated versions of this type of installation is gluing a transom mounted ducer to the inside of the hull.