Depth Finder Accuracy

[Kren]

I never had a reason to believe my depth finder in my 08 X 15 was off but I noticed tonight when leaving my dock that the finder was showing between 1 and 2 ft. Dock is in relatively shallow water this time of year but I know it was deeper then the gauge was showing. Do these gaugues "struggle" a bit with an accurate reading in shallow water or do you think its off?

[MC X-15]

I always thought mine was off too. UNTIL, i was in water i have never been in, and it read 1.5 ft. I looked over and couldnt see the bottom. the water was murky so i figure no way in the middle of this massive bay is it 1.5 ft. 2 second slater I hit a submerged industrial crab trap. That was the end of my day. Wont doubt it ever again.

[Age Fighter]

Sitting still, or at very low speed, the actual water depth would be the more than the finder reads since it is on the bottom of the boat. I am not assuming you were not counting that in -- just mentioning it.

[TMCNo1]

Sitting still, or at very low speed, the actual water depth would be the more than the finder reads since it is on the bottom of the boat. I am not assuming you were not counting that in -- just mentioning it.

Correct, the depth finder tells you the distance between the transducer on the boat bottom and the bottom, not from the lowest part of the boat (prop) or from the surface of the water. To guesstimate the actual water depth from the waters surface to the bottom, just add approximately 8" to 12" to the depth finder reading depending on your amount of draft while sitting still.

[SKIBUMM]

Also remember to factor in the distance from your transducer to the lowest part of your running gear. I had a buddy who thought that the reading was from the bottom of his running gear and if it read 2ft then he had two feet below his outdrive (yes it was an i/o). He thought this right up until the time he ruined his prop and broke off his skeg even though I told him several times that he was not correct in his thinking.

[jdl xstar]

Anyone know that the depth finder stops transmitting after 400 ft? I was on lake fontana- VERY deep lake in western carolina - and it would blink 400 in the deep areas.

[SkiDog]

Anyone know that the depth finder stops transmitting after 400 ft? I was on lake fontana- VERY deep lake in western carolina - and it would blink 400 in the deep areas.

Is that where you dropped Duckguy off with the cinder block tied to his ankle!?:uglyhamme:uglyhamme:uglyhamme

[TMCNo1]

Anyone know that the depth finder stops transmitting after 400 ft? I was on lake fontana- VERY deep lake in western carolina - and it would blink 400 in the deep areas.
There has to be a limit on how deep a depth finder will read and I guess 400' is the limit on yours.

[JohnE]

Is that where you dropped Duckguy off with the cinder block tied to his ankle!?:uglyhamme:uglyhamme:uglyhamme


lmao dog:D

[nmcjr]

Mine actually starts blinking in shallow water, i.e. 4 feet or so--anyone else experience that? I wouldn't mind fixing that if it were possible.

[jdl xstar]

Is that where you dropped Duckguy off with the cinder block tied to his ankle!?:uglyhamme:uglyhamme:uglyhamme

Ha ha!

Mine actually starts blinking in shallow water, i.e. 4 feet or so--anyone else experience that? I wouldn't mind fixing that if it were possible.

I always thought that the blinking in shallow areas was a warning.

[CameronCarey]

One small Correction, the depth finder measures the difference between the transducer and the first item to interrupt the sonar signal...........this could be an air bubble, log, fish or the actual bottom. Murky water and salt water have the effect of slowing down the sonar signal ..........sometimes this can fool a depth finder into reading deeper depths than whats accurate. Other factors that impact the ability to deal with false readings are typically the output of the depth finder (RMS or Peak to Peak wattage) and the cone angle.....a narrower cone angle tends to be better in deeper water, a wider one in shallow water. most depth gauges use a single frequency fairly wide cone angle and are optimized for shallow water............they are also limited on power.....which is usually reflected in terms of a software depth limit which would indicate when the gauge does not have enough power to be accurate..............but if your over 400 feet..............depth isn't really critical any more.

That's my two cents anyway.....

[TMCNo1]

Ha ha!



I always thought that the blinking in shallow areas was a warning.


Usually followed by two words from the driver after a big thud, "Oh Crap!!!!!!".:rolleyes:

[nmcjr]

I always thought that the blinking in shallow areas was a warning.

Maybe it is, but my display goes blank, so it is not flashing 4ft, as an example--in fact I rarely see a number below 5 ft.

[Kingsley X-1]

Mine actually starts blinking in shallow water, i.e. 4 feet or so--anyone else experience that? I wouldn't mind fixing that if it were possible.

yea mine craps out at about 4 feet as well.

[ProTour X9]

Maybe it is, but my display goes blank, so it is not flashing 4ft, as an example--in fact I rarely see a number below 5 ft.

Does it say SHAL?? (shallow) mine does when its under 5 ft...

[nmcjr]

Does it say SHAL?? (shallow) mine does when its under 5 ft...

Not completely sure, I think it just shows " - - " but will have to look next time out. If it is by design it is kind of a bummer because there is a big difference between 5 and 1 feet! This is usually an issue at ramps and coming up to the beach etc, wish it were accurate to 2 feet or so.

[SkiDog]

Mine says 'Get the f--- outa here'!:D:D

[Kingsley X-1]

i have seen mine flash shallow once or twice but normally it just starts blinking the last acurate number that it had...if it does that then i do what dog said'Get the f--- outa here'!:D:D

[ProTour X9]

Not completely sure, I think it just shows " - - " but will have to look next time out. If it is by design it is kind of a bummer because there is a big difference between 5 and 1 feet! This is usually an issue at ramps and coming up to the beach etc, wish it were accurate to 2 feet or so.

Well no mine flashes SHAL, while it still gives you a reading like 1.5 ft e.g.

[flashydubber]

You can adjust the shallow water warning with VDIG.

Also my VDIG doesn't show anything above 100feet deep... just defaults to 99.99 feet.

I guess it's not too important to know how deep the water is at that point unless you want to scuba dive for the sunglasses you just dropped? ??