Losing depth readings after 80m please help!!

[Fishmn28]

Hi all,

I purchased a boat 2 years ago with a raymarine e80 screen, DSM 300 sounder module and thru hull airmar b164 transducer. Fantastic soundings at all speeds and at depths up to 80m. I've been going further out lately and started to notice that I lose all info after I go deeper than 80m, drifting or going over slow. Heard about issues with the dsm 300 module so I got a new CP370 from raymarine. No difference. It's 1kw setup so it should do 500m easily. I've increased ping speed, changed from 200 to 50hz, left it in auto settings, turned it off, reset settings, increased gains. Have I missed anything. The depth display just flashes and shows nothing until I go shallow again.
Any ideas??

[barnakiel]

One thing that comes to mind is maybe the transducer is fouled.

Another thing is if you have a drop off at say 60m. How deep is the water actually when you lose the readout?

b.

[Fishmn28]

I thought it might be the face of the transducer but when I inspected it there was no sign go of fouling. Maybe a wipe or light sand just to make sure. 50-60m is where I do most of my soundings and it's perfect. Picks up everything on the bottom, but at 80-100m it starts blinking and reads nothing. My cheap hummingbird is still reading 100

[rwidman]

Originally Posted by Fishmn28

Hi all,

I purchased a boat 2 years ago with a raymarine e80 screen, DSM 300 sounder module and thru hull airmar b164 transducer. Fantastic soundings at all speeds and at depths up to 80m. I've been going further out lately and started to notice that I lose all info after I go deeper than 80m, drifting or going over slow. Heard about issues with the dsm 300 module so I got a new CP370 from raymarine. No difference. It's 1kw setup so it should do 500m easily. I've increased ping speed, changed from 200 to 50hz, left it in auto settings, turned it off, reset settings, increased gains. Have I missed anything. The depth display just flashes and shows nothing until I go shallow again.
Any ideas??

Why not ask the manufacturer?

What sort of boating are you doing that you need to know depths greater than that? In my boating experience, I only need to know that it's shallow enough to anchor and deep enough that I won't go aground.

[Nightsky]

Originally Posted by rwidman

Why not ask the manufacturer?

What sort of boating are you doing that you need to know depths greater than that? In my boating experience, I only need to know that it's shallow enough to anchor and deep enough that I won't go aground.

Prawning in BC is often carried out in 90 to 100m depths.

[GordMay]

Greetings and welcome aboard the CF, Fishmn.

[barnakiel]

It could also be that the bottom is of the type that does not generate a strong response?

I mean probably the returning signal is a proxy for radio hardness of the bottom. Say rock can be read at 100 m but ooze at only 80?

Our in-hull mounted (but thru hull type) Ray reads to about the same depth as your sensor but it did read to about 120 meters back in Sweden.

So, my guess is age/condition of the sensor may count or else there is a big variation in how strong an echo you get depending on what the bottom is made out of.

b.

[El Pinguino]

My old Stowe sounder would only show to 80 metres. My newish Raymarine ST60+ runs out to about 140 metres and then just sits on the last reading with a small 'last' in the top left corner...... until it picks up a fish or some kelp or a thermocline and shows 3 metres and scares the bejaabbers out of me....

[DeepFrz]

Fishmn28, check all your wiring connections and battery voltage.