False bottom reading on depthfinder !!!!!

[ERABBIT]

I have a 788ci , that when I'm fishing deep water I set it up to just show the top 90 feet of the water collum. It's OK from shallow till about 350' then around the 400 + feet I'll start getting false bottom read outs. I turn unit off and once in awhile it will work OK but latley no so. I fish Seneca lake with depths up 600+ feet and I fishing blind now when I try and fish the deep water...... I'm in "Advanced" mode and did change the "water type" to deep salt" or else I could not even get a bottom reading over 200' of water............and ideas ?????

[DEFIANCE1]

I have the 787c2i and have the exact same problem that you are having...I havent found a fix for this either. When it happens, the sonar is still reading correct and you can set you bottom depth to the top 150ft and still read your sonar but the depth is not reading correct. Still marks fish and bait at the correct depth. It seems to do it more when I have the bottom limit set to auto. If anyone has talked to humminbird or found a fix for this it looks like it could help a few people. I thought at first it might be some type of interference from the motor or fishhawk but ive tried turning the boat off completly as well as all electronics and it still does it.

[Iceman]

Is your transducer pointing directly down, or does it need to be tipped forward or back? Look at the water line on your boat & see if the bottom of the transducer is parallel with it. If not adjust it.

[Yankee Troller]

We see similar issues guys. We run ours in manual mode and set the bottom to 125' or 150' (over deep water) and everything works fine. I'm not sure what the deal is with that. I know I am running a different transducer than you guys, so I wouldn't think it's the transducer. Sometimes you have to play with where you set your bottom when your shallower to get the clutter off the screen, but once you do the unit works fantastic. Some other settings we/you should have are:

Max mode ON

Water Type SALT DEEP

Surface Clutter 3 or 4

Noise Filter - Play with this setting to get the best results

Fish ID OFF

If I think of any other I will let you know. I will also try to record his issue and send the recordings off to Humminbird in the near future to get their take on it. Also, be sure your running the latest software updates. You can get it off their website.

[ERABBIT]

DEFIANCE1

if mine did what yours is doing I could easly live with it all I want to see at this time would be the top 90 to 120 feet and care less what the bottom reading would be. BUT mine will read or seem to lock on a cannonball say at 50' and not read any thing below that. Then some times it just jumps around all over.... thanks for the reply

Iceman , this unit is rated for 1,500 feet so if I did have it tilted back to far and it was NOT reading bottom why would it affect the top 90 feet I have it set to read ???? I am having trouble reading my deepest cannonball and put one more click up to see if it was being blow out of the cone angle the last time I was out........but when I was putting that rigger down I was NOT picking up the ball at ALL............so I put it back that click , marked the side of the mount on the boat and tilted it so the cone angle was a tad more in that direction......so yes I don't think it was parallel but should be much closer now....thanks

Yankee Troller

I'm running a quadbeam and I also have the dual beam that I could switch head units to get to but most of the time I'm just running on the 83/200 anyway......

Max mode ON

Water Type SALT DEEP

Surface Clutter 3 or 4

Noise Filter - Play with this setting to get the best results

Fish ID OFF

I have it on the salt deep and fish ID has always been OFF.......

I'll have to check the other three not sure.......thanks

[ERABBIT]

I just sent them this link hope they take the time to help like you guy have...........

[ERABBIT]

Max mode ON

Yankee Troller I can't find this in my book anywhere did you mean "Advanced mode" ???

I think that the "Noise Filter" may be the problem I'm almost sure I turned that OFF..........and after reading what its for may also solve my higher speed crazy reading when I slow down.........

Thanks again........

[ERABBIT]

I ran her out today with the adjustment you put up and it worked OK........I was still having issues tracking my cannonballs.......made one more change and ........WOW....that did it but I get so many small fish marks it makes me go.....Hmmmmmmmm!!!!!!.........SwitchFire Mode max tracks cannonball great............in the clear mode not wothna crap..............but at least I can track them now and maybe dropping some of the other setting I can fine tune it........

Thanks everyone............

Oh if ya want a good..... ...... I'll post the usless replies to my e-mails with the same question stated in the top post that I got from HB support.... .........if it's broke they take care of ya 1...2...3..... .....ask for help with a problem.....

[Duckman1]

I have a 788c just getting into trolling. I also can use a quadrabeam. But use what came with the finder. R there benefits to this transducer. I will also be changing some of my settings.

[ Post made via Android ]

[Yankee Troller]

That's the setting.....switchfire needs to be in max mode.

[ Post made via Android ]

[ERABBIT]

I have a 788c just getting into trolling. I also can use a quadrabeam. But use what came with the finder. R there benefits to this transducer. I will also be changing some of my settings.

[ Post made via Android ]

Read up on it that's what I did then bought one thru Cablea's for $70.00 I thought it would take me one level higher without paying a lot more money for the next level unit...........knowing what I do now I would ask around about a Airmar transducer......right now most of the time when things are working right on the depthfinder I'm 85% of the time using the 83/200 beam........I used the quadbeam a few time but it cut the screen down making it harder to see marks...........in all fairnest I have NOT run it enough to say it worth it............sound GREAT when you read what it will do and may be good on a bigger screen than I have.............

[ERABBIT]

That's the setting.....switchfire needs to be in max mode.

[ Post made via Android ]

YT thanks again your help soloved two problems I was having...... if I see ya around some time I'll get ya a....

[Shipwreckworld]

I believe what is happening to your depth readings is being caused by severe thermocline.

This is a thin but distinct layer in which temperature changes more rapidly with depth than it does in the layers above or below.

The month of August is probably the worst month for thermo layers to occur in our lakes.

There might actually be several thermo layers in depth. This month the thermocline may extend down to around 85 feet or so.

The thermocline causes sonar signals to be reflected back because there is a density difference of the warmer and colder water above and below the thermo layers.

Your sonar is probably picking up the first strong return signal from this thermo layer and locking on to it as if it were the bottom.

If you have a temperature probe with a +100 feet of line drop it down slowly and you can observe where the thermocline(s) are located.

Hope this helps explain what you are seeing.

NOTE

Should you have encountered any bumps or hangs off the bottom of any lake please contact me.

I will check them out and post them on the WRECK FINDER portion of our website: http://www.shipwreckworld.com

[ERABBIT]

Shipwreckworld thanks for the info , here what was going on today and what I did to correct it :

While fishing today back into the waves we were getting false reading .......5'......9'....tried turning it off and back on ...............still had the problem ......long story short........clicked on "Noise Filter".......decreased the reading (lower number) bamb it came right back with out shutting down..................later same problem only reading that we were in 9 feet of water............clicked on "Noise Filter".......lower it some more and imediatly (sp) it was working right.......

[ac holmes]

Hi ERRABIT,

 

I have the same unit and it does the exact same thing as you describe.  I updated the firmware from the website and it is much better now, but still does the glitch 0-2 feet bottom once or twice each trip on the water.  I have tried everything mentioned above, and now believe it is a software/firmware issue, because it is better after the upgrade.  Before the upgrade, I lost the surface temp read but now that is steady and accurate.   The company must know about the problem and will probably get it fixed, so regular upgrades to the firmware may eventually fix it.

It is a great piece of equipment apart from the issue mentioned.  I just turn it off and reboot, but it is a pain in the butt.  I am in the software business, so I know about the reluctance of admitting a problem to the end user...it can lead to a business disaster, so we offer upgrades and talk about "bug fixes" instead.

[rustyrat]

My raymarine unit was doing the same thing this weekend. Locking on to a rigger ball or temp. I solved the problem by turning the power and the gain way down and then adjusting both back up a bit. Still marked bait and fish excellent even with the power and gain set to 10 on a scale of 100.

Might help if you play with those settings. Its frustrating, I know.

RR