Raymarine Dragonfly

[igotpron]

Originally Posted by Fomen

I'm thinking that your signal is going to be slightly degraded regardless of what unit you use because you're transmitting through the plastic transducer protection cover. Those transducers are designed to be mounted to the transom of a boat, and angled just right to reflect what's directly below the boat when you're not on plane. Typically, they are unobstructed. When I was in the Navy, I was a Sonar Tech. That's essentially what your transducer is. It's a simplified version of Sonar (Sound Navigation and Ranging) technology. Sound travels 3.5x's faster under water, and there are 3 naturally ocurring mediums that effect sound travel. These are temperature, pressure, and salinity. The designers of these units use mathematical algorithms to determine averages for particular conditions. Usually the water temperature at the surface is factored in to give you a reasonably accurate reading. What they don't account for is transmitting through a piece of plastic or resin. They do make thru-hull transducers, but these transducers aren't thru hull. JohnMckroidJr's fix for this is the best scenario (IMHO).

I believe the lowrance transom mounted transducers list shoot thru hull capable, they even sell the epoxy to mount inside the hull. But for as much as we pay for the finder you defenatly don't want to degrade your return.

[Fomen]

Originally Posted by igotpron

I believe the lowrance transom mounted transducers list shoot thru hull capable, they even sell the epoxy to mount inside the hull. But for as much as we pay for the finder you defenatly don't want to degrade your return.

I did not know that. It's good to know. I might have to look into the Dragonfly transducer specs and see it it's listed as "thru hull" also.

[JohnMckroidJr]

Originally Posted by igotpron

I believe the lowrance transom mounted transducers list shoot thru hull capable, they even sell the epoxy to mount inside the hull. But for as much as we pay for the finder you defenatly don't want to degrade your return.

Garmin makes a kit for through hull installation also, but let's face it, It the echo has to go through a layer of plastic(twice...out going and receiving), it is going to be weaker return.