Depth reading flashing/blinking

[deer30084]

I have a Garmin echomap54dv. The depth reading flashes or blinks at speed. It doesn't do this at any particular depth. It could be 14' for instance, or any depth, in the St Marks channel or bay. It does it in shallow water and deep water. It will continue to flash or blink until I bring the boat to a stop after a couple minutes. Sometimes I get impatient and turn the unit off and on and reset it that way. The transducer is the external transducer supplied with the echomap54dv mounted at the stern and I believe it to be mounted properly. My boat is a Cobia 174. Is there anyone else out there that has experienced this type of problem? If so, can it be fixed and how?

[crappielimits]

Check transducer for trash. Next check transducer mount.

[zload]

Recent install or sudden change?

[bman]

Last time that happened to me it was the bracket getting loose!

[fishinfool]

Some boats produce bubbles that pass under the transducer which interferes with the units ability to read an accurate depth. You can try to set the transducer below the transom to help with it. Good luck. I have never been able to stop it with my Carolina Skiff as it is a common problem with the hull.

[deer30084]

It's a recent install. My previous Garmin 441s was doing the same thing. It had a shoot through the hull transducer. Figured if I replaced the 441s with the echomap54dv and an external transducer, things would be better. They're not. Same problem. The bracket is not loose. I mounted the transducer myself. I did a lot of reading before I drilled holes in my boat. Maybe later I can post a picture of where exactly the transducer is mounted. I don't want to lower the transducer because I think It will cause more turbulence. I tried calling Garmin and I got no help there. Spoke to the guys at Bass Pro where I bought the new unit and didn't get any help there either, hence the post to see if it's a common problem and if anyone has a solution. I thank you all for your comments.

[Steve Stinson]

My Eagle depthfinder does the same thing. I believe the unit is loosing signal and blinking the last good reading it had. When the signal from the transducer gets received again, it will quit blinking and start reading the accurate depth again. There can be a lot of reasons.

1. Trash or weeds on the transducer.
2. A hull fitting or something else obstructing the water flow in front of the transducer.
3. A corroded or loose cable connection to the back of the unit weakening the signal.
4. Banging the transducer on a rock, oyster bar, or the boat trailer, changing the angle of the transducer.
5. A crimp or pinch in the transducer cable between the transducer and the dash unit.

These are just some of the ones I've experienced. I am sure there is probably more. I haven't found a unit yet that will keep a strong signal under all speeds and conditions. The most reliable ones, believe it or not were the old round flasher units.

- Steve Stinson

[zload]

Getting really shallow will cause this, as in 3' or less and sometimes as you drift deeper it will clear up but most of the time I had to cycle my machine off/on to clear it and then it would work again. I guess the programing is basically saying if you don't realize you are in 2' of water you are on your own, maybe the signal return is too fast for it to process properly

With that said...

Making sure the transducer is at the correct angle relative to the bottom (not the hull bottom) is one thing to check, sort of hit or miss when installing as the natural thing to do is set it relative to the hull while on the trailer but it is probably not the same angle the hull is at when it is in the water. I moved mine while on the water several times to get it dialed in. Make sure the transducer is not slipping and changing angles especially if it catches on grass, I was surprised how tight I had to get mine to stop the floating grass from moving it.

I never had a great bottom read on my original transducer and it would break bottom lock as far as the digital readout regularly until I replaced the transducer and moved it. Turns out once I got down and looked at it, the original installer (not me) had placed it directly behind a partial strake, it didn't come all the way back to the transom but it was still causing disturbed water flow and a crappy bottom read. My transducer went bad so when I replaced it I moved the location about 3" over and now it works fine. I'll still lock up when super shallow on occasion but not as frequently and it usually clears up as soon as I get back into deeper water.

[deer30084]

it I moved the location about 3" over and now it works fine. I'll still lock up when super shallow on occasion but not as frequently and it usually clears up as soon as I get back into deeper water.

zload: Did you move it about 3" over to the starboard side or towards the center of the hull? Mine is located about 2" starboard of the partial strake. I have one of those partial strakes too that doesn't come all the way back. If I move mine over towards starboard, I'll be under the ladder. If I move it the other way towards the center of the hull, it will be behind the partial strake or port of the strake but behind the motor. Not much room to play with. I'll try to post a couple pictures of my installation tonight. Thanks!

[zload]

Moved mine to the starboard, trying to stay away from the prop wash. Got closer to the trim tab but does not seem to be an issue.

[deer30084]

Tried with the picture. Not "super easy."

[deer30084]

A few details were missing in the video about posting a picture. Like resizing the photo so it's not too big. Anyway, here's my transducer. You can barely make out the partial strake just to the left of the transducer.

[crappielimits]

I believe that's your problem. It's hard to tell from picture but it looks high. Also may not be level in water looks close to the V and not low point of hull. Is there a pad or second hull? Are those trim tabs? Need more pics.

[fishinfool]

Agreed, it looks a little high.

I found the following transducer mounting information. It looks like someone has done some extensive research on the subject. http://www.sternmate.com/Where.html

[grasscarp]

We put a man on the moon 50 years ago but still cant get accurate depth information. Every boat i have ever been on does this.