GARMIN CV23-TM Transducer Placement

Electrical and electronic topics for small boats
SeaClassic16
Posts: 9
Joined: Tue Sep 24, 2019 2:59 pm

GARMIN CV23-TM Transducer Placement

Postby SeaClassic16 » Tue Sep 24, 2019 3:05 pm

I just installed a new SONAR unit my 1964 16-foot (Boston Whaler) boat The transducer is a GARMIN CV23-TM, a long unit.

The depth sounder loses the bottom at speed. The transducer is kicking up a rooster tail.

I mounted the transducer on the starboard side of the boat using a transducer block I fabed up at home. The block sits just above the bottom of the transom and the transducer is just a bit lower than the transom. I did look at the transducer tips page I found in another post but it didn't quite address this.

Give me a any thoughts [why the GARMIN depth sounder loses the bottom when the boat is at speed] or tips [to improve the bottom echo on the GARMIN depth sounder when the boat is at speed. [They] would be appreciated.

Also: where have you run your cables to avoid interference?

Aside from the rigging tunnel it seems like every other option is going to be messy looking and a bit in the way.

Thanks.

jimh
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Location: Michigan, Lower Peninsula
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Re: GARMIN CV23-TM Transducer Placement

Postby jimh » Wed Sep 25, 2019 11:24 am

On an open 16-foot skiff like a 55-year-old Boston Whaler the only concealed path for a SONAR-to-transducer cable is the rigging tunnel.

Experiment with the depth of immersion and angle of the transducer. Often small changes have profound effects.

Contact GARMIN for advice specific to their particular SONAR transducer.

If you chose the transom location correctly with regard to distance from the keel centerline and freedom from aerated water at speed, the depth of immersion and angle of the probe are all that is left. If you chose a bad location on the transom, move the location. The closer to centerline the better, as a rule.

jimh
Posts: 11673
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
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Re: GARMIN CV23-TM Transducer Placement

Postby jimh » Wed Sep 25, 2019 1:09 pm

Re the block you fabricated and installed on the boat:

If the block is on the transom, its lower edge should be in the same plane as the transom. If not, then water coming off the hull bottom is probably becoming disturbed before it gets to the transducer. I would make the bottom on this block fair with the hull bottom.