Found the limits of my DownVu sonar

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chris moody
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Found the limits of my DownVu sonar

Post by chris moody » 16 Sep 2018, 13:37

I just spent the week on the west coast of Scotland. On Friday we went out to visit Crinan and Ardfern. The sonar was happily showing the depth at speeds up to 30kts which I was very happy with. But the sonar lost signal at 113 metres depth. We deliberately took the boat over a depression in the seabed that was charted as being 140 metres below chart datum, but the sonar could not bounce a signal back from that depth, even when stationary. It just kept flashing 113m at me. I think I need a more powerful depth finder :)
Chris Moody
Tigga 2: Ribcraft 4.8 Honda BF50
Tiny Tigga: Takacat 3.4 Tohatsu 9.8

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Re: Found the limits of my DownVu sonar

Post by Stray » 18 Sep 2018, 10:08

Did you try normal/chirp sonar as well?

chris moody
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Joined: 24 Mar 2015, 12:19
Boat Make: Ribcraft 4.8 Takacat 3.4
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MMSI Number: 235900806
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Re: Found the limits of my DownVu sonar

Post by chris moody » 18 Sep 2018, 11:14

Yes tried that as well. Neither downview or normal sonar would work over 113 metres. Once the depth dropped to 112 metres it started working again.

It would be interesting to find out at what depths others lose their sonar readings.
Chris Moody
Tigga 2: Ribcraft 4.8 Honda BF50
Tiny Tigga: Takacat 3.4 Tohatsu 9.8

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Re: Found the limits of my DownVu sonar

Post by Stray » 18 Sep 2018, 13:30

It's strange that it lost the bottom so soon, my Lowrance has a maximum working depth of about 300m (not that I've tried it). Did you have the correct depth setting, I usually set mine to 60ft, but when I stray into deeper water I lose bottom until I change the settings.

chris moody
Supporting Member
Posts: 1661
Joined: 24 Mar 2015, 12:19
Boat Make: Ribcraft 4.8 Takacat 3.4
Outboard: Honda BF50 Tohatsu 9.8 2s
MMSI Number: 235900806
Location: Braunston & Porchester
Has thanked: 50 times
Been thanked: 192 times
Contact:

Re: Found the limits of my DownVu sonar

Post by chris moody » 18 Sep 2018, 13:32

It was on auto.
Chris Moody
Tigga 2: Ribcraft 4.8 Honda BF50
Tiny Tigga: Takacat 3.4 Tohatsu 9.8

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