Transducer Location

[TunaFish389]

Looking for advice on transducer mounting location. They say to use starboard side with standard rotation. Have Speedo sensor there also. Which number? Thanks.

 

[dingbat]

3 and 4 are out right off the bat.

#1 if it’s outside the diameter of the prop.

If side scan, you have to be X” from center of prop for angles side scan beam to clear the lower unit

 

[TunaFish389]

Its not side scan, a Garmin dual beam transducer. Would the Speedo sensor be the idea spot if it wasn't there?

 

[dingbat]

Its not side scan, a Garmin dual beam transducer. Would the Speedo sensor be the idea spot if it wasn't there?

Strakes cause turbulence. Bad place to mount a transducer

 

[TunaFish389]

Ok so my manual says "as close to center without being in the path of the propeller". Does this mean when the drive is in full turn also? If so number one position won't work. What's my next best location without redesigning the boat if full turn is a factor? Thanks.

 

[dingbat]

Ok so my manual says "as close to center without being in the path of the propeller".

To ensure the best performance, the sensor must be in contact with aeration-free and turbulence-free water. Mount the sensor on the transom as close to the center line (keel) of the boat as possible.

Do not mount in an area of turbulence or bubbles: Near water intake or discharge openings; Behind strakes, struts, fittings, or hull irregularities;

Mount on the starboard side at least 75mm (3") beyond the swing radius of the propeller. If you have a 20" diameter prop, mount the transducer at least 13" from the center line.

 

[TunaFish389]

Ok that is better than what my manual says. Thanks.

 

[TunaFish389]

I have a 14.5" prop, which would be 10.25" with the added 3". I am looking to start the transducer port side at 12" from centerline, the starboard side will be 2" from the start of the lift strake (where the flat spot starts). Is this idea.. Move close to lift strake? Or move closer to prop. Thanks so much for the info so far.

 

[dingbat]

I have a 14.5" prop, which would be 10.25" with the added 3". I am looking to start the transducer port side at 12" from centerline, the starboard side will be 2" from the start of the lift strake (where the flat spot starts). Is this idea.. Move close to lift strake? Or move closer to prop. Thanks so much for the info so far.

Have someone run the boat while you look over the transom. Easy to tell “clean” water from disturbed

 

[harringtondav]

Hope this adds some value to the thread. Mostly horse pucky luck on my part. My dealer RTV'd this external flat iron transducer to my bilge floor. Not per instructions. It should have been epoxied, but he wasn't quite ready when I picked up the boat so he winged it.

Iffy signal that caused my first prop bend, so I called the depth sounder mfg., and they gladly sent me the transom bracket for gratis. This was over 20 yrs ago, so I don't remember the fine mounting details mentioned above. ..Thinking I just cleared the trim hoses and kept it as low as possible. 7.5-8" starboard of center.

End story: It's worked like a dream. So well that if ever buy a new boat, I'll set up an external transom mounted sender. Only issue is when I hit hard big boat wakes, or severe chop, I loose signal. Throttle down, regain signal, back to boating.

 

[TunaFish389]

I have my kids and dog.. Neither one I trust to drive.. I might ask the dog..

 

[TunaFish389]

I do know it will be before the strake .. I learned that. And how many different strake a boat can have.. I believe mine are lifting strake.

 

[TunaFish389]

Went with number one spot. Keeps depth at my max speed (33 MPH). But only took out once so far. Looks to be skimming water at speeds the time I glanced. Thanks.