Depth Sounder anomolies

[Capt. Kermie]

removehtml]I have an inexpensive SeaEagle FishFinder/Depth Sounder that seams to choose when it wants to work or not. At the beginning of the season I have the transponder cleaned off and while at the slip it works fine. I get out on the water and it still works fine, then out a bit further and sometimes it decides to lie to me and tell me I am in shallow water which I know I am not. I turn it off then on again and it works for a while then goes back to telling me lies. I cannot rely on a depth sounder that lies to me for fear it will lie at the worst time. Does anyone else have issues with their depth sounder fluctuating depths that do not coincide with the charts. Perhaps I need a replacement or maybe it has to do with environmental anomolies, I am not sure at this point I am in the PNW, 49th parallel, west coast. Just wish to know if others have this problem and how to address it.Error: Error: expected [/URL], but found [/removehtml] instead[/removehtml]

 

[Jadedcrew]

Depth Sounders

Does it work reliably in shallower water (0-100')? It really shouldn't be called a depth meter, but a 'How Shallow is it?' meter. My Autohelm (Raytheon) depth (1992 vintage) will occasionally show shallow readings when in very deep water. I attribute this to thermal layers (different temperatures), or to a large fish. I sail in the PNW, and this happens from Seattle to Desolation Sound (as far as I have gone). So your Sea Eagle is probably fine.

 

[RichH]

Sensitivity

On most depth sounders there should be an adjustment for transducer sensitivity .... so you can 'de-tune' the unit so you dont get false readings from extremely dirty water or a bottom that has a lot of very soft and gelatinous 'goo'. Typically on most all depth sounders you often have to make 'adjustment' based on how 'hard' or 'soft/gooey' the bottom is or you can get such false reading problems.

 

[MoonSailer]

Other Boats

Since the thing works by listening to sound returning from the bottom and using a timer to calculate the time and thus distance any interfering sounds can cause problems. I have noticed this on my boat that someimes when other boats are around the depth sounder messes up. Another problem might be bubbles. If the placement of the transducer is where bubbles can form under the hull. I assume that the units use specific patterns of makeing sounds and then listening for the echos...if someone nearby is using the simular frequency then you have interference, But sadly it could be your unit. By old unit would give spurious readings when the battery was low and then finally it gave no readings at all and I bought a new unit. I've noticed really weird readings when going through locks. I assume that the sound is bouncing all over the place off the solid concrete walls. This is also where I've most noticed the "other boat" effect. Sensitivity settings will affect readings a lot. On one unit I had to play around with it to get good results. With a soft bottom more sensitive and less sensitive with a hard bottom.

 

[Landsend]

all depth finders show anomalies not and then...

inexpensive units that have less sophisticated circuits show them more. It just may be time for a new unit.

 

[Warren Milberg]

If the depth sounder is

inexpensive, it may be that it's nearing the end of its natural life. The corrosion, crud, vibration, and weather take their toll -- on man and machine.I had an old C&C years ago that had an even older Moor EMS depth sounder. Never saw anything like this beast. It had an elaborate back that had a keypad for adjusting it. It, too, had anomalies. Try as I might to adjust them away, they were persistent. I then realized that the anomalies only happened in a rather large pie-shaped area of the Chesapeake. One of the "peaks" of that pie was a shore based Navy UHF/ULF and satellite control antenna farm.... I assumed that whenever they were transmitting, my depth sounder was being interferred with. I soon replaced the old depth sounder with a newer one that was either shielded from Navy transmissions, or operated on a different frequency. Sounds like it might be time to replace your old unit, too.