Thru Hull vs. Transom Mount Transducer

[Five O'Clock]

I'm sure you've all seen my posts about buying a fish finder... now that I have it picked out, I have the option of thru hull or transom mount transducer... The thru hull is more expensive than the transom mount, which leads me to believe, maybe it's better quality or better for the fish finder.

I tried searching threads for this topic but I couldn't find any....

The fishfinder i'm going to purchase is the Furuno LS4100 for saltwater fishing, I heard www.airmar.com makes great transducers so I was thinking of going through them.

suggestions?

 

[fdmsiv]

Re: Thru Hull vs. Transom Mount Transducer

Thru hulls are better in some ways, but in the end if installed right, either will do just as well. The caveat is that if they are installed correctly.

This is just my opinion, there will probably some that disagree, but here is what I think. If your boat is less than 25 ish feet I would avoid thru hulls for 2 reasons. Boats of this size and larger are usually subdivided with bulkheads that will prevent/slow down the sinking of a vessel due to a thru hull failure.

The second reason is that most boats of this size and larger will have more of the hull in "clean" water. By "clean" I mean that you have a nice flow with no air bubbles or turbulent flow. Bubbles and turbulence with cause the transponder to give funny or messed up readings.

 

[jevery]

Re: Thru Hull vs. Transom Mount Transducer

I like thru hull installations for a couple of reasons. First less exposed wiring. With a transom mount you will have to route the wire through the hull at some point, usually high in the transom or up over the transom into a splashwell opening. I hate drilling holes in my boat. Second I think they read better at speed. At speed, the water under the center of the stern is about as turbulence free as you can get. True, you can usually eventually get a transom mount to read well, but the water flowing off the hull creates a lot of disturbance and it?s tough to get just the right height where the transducer is in the water, but not creating a lot of spray. Many will say that a transducer in the water is more sensitive and will show more detail than one receiving the signal through 3/8? of fiberglass, but both of my through hull installations seem to show as much detail as my last transom mount installation.

 

[dingbat]

Re: Thru Hull vs. Transom Mount Transducer

On my last boat I had a Sitex CVS 106MkII with a stock transom mount transducer. The transducer worked fine but it had a lot of surface clutter and you couldn?t pick up individual fish very well when running over say 20 kts. I changed over to Airmar P79 shot thru and had good clean water all the way to WOT at 40kts.

On my new boat I have a Furuno FCV585 coupled to an Airmar B164, tilted angle, thru hull transducer which is a great transducer. You get all the benefits of the standard thru hull transducer but since its flush mount you don?t need a fairing block hanging off the bottom of the hull. The perfect installation on a trailered boat.

For your unit I would recommend the Airmar B60 tilted element transducer which is a 600 W unit.
http://www.airmartechnology.com/airmar2005/ex20/RMProducts/ElectCat.asp?ProdID=36&Man=All&PageNo=67

 

[drewpster]

Re: Thru Hull vs. Transom Mount Transducer

I was also looking at transducer you mentioned (Airmar). What kind of price range are we talking about for this type?

 

[dingbat]

Re: Thru Hull vs. Transom Mount Transducer

I was also looking at transducer you mentioned (Airmar). What kind of price range are we talking about for this type?

They are not cheap and they are 200/50kHz units.
The B60 (600W) is $225 and the P79 (600W) is $100

 

[TBarCYa]

Re: Thru Hull vs. Transom Mount Transducer

When you say thru-hull do you mean one that requires drilling a hole in the hull so part of the transducer is in the water or do you mean a shoot-thru where the whole transducer is inside? I took the transom mount that came with my Garmin and installed it as a shoot-thru. Right now, I'm on my 3rd method of installation but I think that's because I didn't listen to the advice I was given when trying the first two. This one should work out well.