How to Read a Fishfinder

[TonyD]

Hey! So, I am a rookie with these fancy electronics. When I bought my Grady 10 years ago, it came with a fish finder on it already installed and I didn't have to do anything and it worked. Although it was an old finder, black and white screen, I didn't have colors and cool features and pretty simple to user and read. But since it finally crapped out on me I went ahead and bought a Garmin echo 551dv. I also installed it myself. I followed the directions on how to install the transducer and it appeared I had it right.

But now I am in the water and I got a nice little rooster tail from the transducer. I have read that perhaps its too low. But before I start drilling more holes in my transom I'd like to know if that is really the solution - I'll start off with the image I see on my fish finder. I can't say if this looks right or not, seems like a lot of noise.. any help from anyone who can help a rookie out with their new electronics would be greatly appreciated! So - what in gods earth am I looking at here??
(When I can, I'll put the boat on the trailer so I can get a shot of the transducer install to help with any info)

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[DennisG01]

The picture on the trailer will be more helpful.

These should all be in the directions, but a couple things come to mind...

-- The bottom of the ducer (front) should only just barely be below the bottom the hull - almost skimming. The aft end of the ducer should be very slightly below the front of the ducer.

-- It should be mounted in an area where there is "clean" water... not too close to a chine/strake/edge... and no thru-hulls in front of it. Also, not too close to the engine... usually at least a foot away.

 

[Doc Stressor]

Dennis gave you good advice. I'll just add:

1. If your images were captured while the boat was on plane, that's about what you can expect from your Garmin. There should be much less mid water clutter when you are moving at only a few mph.

2. Garmin sells a shield for that transducer that will eliminate the rooster tail.

3. The SV2 hull on a Grady presents some unusual problems for a stern mounted transducer. The forward strakes that don't come all the way back produce turbulence under the smooth part of the hull. Sometimes moving the transducer only an inch or so to the left or right can make a big difference.

4. I've found that setting the transducer back a bit with a Sternmate (http://www.sternmate.com/ or a Sternsaverhttp://www.sternsaver.com/ gets rid of any turbulence problems. With a Sternmate, my transom mounted transducer follows bottom at speed even better than my through hull B30.

A picture of your current mount would be helpful.

 

[TonyD]

Thanks, Dennis and Doc - yeah, let me get her on the trailer to take a picture of the transducer mounting - it's supposed to rain tomorrow so probably over the weekend.

I did know about the garmin shield to eliminate the rooster but I didn't want get it until I knew the mounting wasn't my issue. I was reading if the transducer is too low it will give a tail like that. As for the sternsaver, I did want to go that route initially but part of my problem with that is when I removed the old transducer, I plugged up the old holes with some 5200 and put the screws back in. The stern-saver won't mount flush to the transom taking this into consideration.
I suppose there is a better way to do this though.. :hmm

ohh, also, I realized that I posted two of the same pics, there was a third one. This one here I am just sitting in my slip (with 3 feet of water and very weedy). I was wondering what all that information up top was though?

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[TonyD]

Okay, so I put her on the trailer this morning - here is what I have:

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And this one here is a pic of the sonar image going about 1000 RPM's.

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[wahoo33417]

Tony: Looks a tad low to me. Does mounting bracket allow you to push it up some? Looks like outer screws on bracket allow for adjustment, but not sure about that center screw.

 

[seasick]

Hey! So, I am a rookie with these fancy electronics. When I bought my Grady 10 years ago, it came with a fish finder on it already installed and I didn't have to do anything and it worked. Although it was an old finder, black and white screen, I didn't have colors and cool features and pretty simple to user and read. But since it finally crapped out on me I went ahead and bought a Garmin echo 551dv. I also installed it myself. I followed the directions on how to install the transducer and it appeared I had it right.

But now I am in the water and I got a nice little rooster tail from the transducer. I have read that perhaps its too low. But before I start drilling more holes in my transom I'd like to know if that is really the solution - I'll start off with the image I see on my fish finder. I can't say if this looks right or not, seems like a lot of noise.. any help from anyone who can help a rookie out with their new electronics would be greatly appreciated! So - what in gods earth am I looking at here??
(When I can, I'll put the boat on the trailer so I can get a shot of the transducer install to help with any info)

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Those images look OK but you might want to lower the sensitivity a tad. Turn off Auto Sensitivity if you have that option and adjust the sensitivity manually to reduce clutter. Play around with sensitivity and noise reduction if that is also available

The major question is not so much the display but what happens as you speed up. Do you loose bottom? If not you are 90% there.
If you do, you may or may not be able to adjust to maintain bottom at speed. I also think ( but it is hard to tell) that the ducer is a bit low but your picture look good so leave it for now. The bottom of the ducer should be parallel to the sea floor at speed so if your hull angles up when planing as most do , you might try tilting up the back of the ducer a notch. Again, if you don't loose bottom, don't change that angle either.
Depending on several factors it might be difficult to maintain bottom at WOT and max speed but you should be able to do OK at cruising speed.

 

[Fishtales]

One idea. If you do have to move it, maybe mount a piece of starboard using the existing holes. Then mount the ducer to the starboard where you want it.

 

[dstarok]

Garmin makes a spray shield that mounts on top of the transducer to reduce the rooster tail.
Or, you can make your own.... http://www.thehulltruth.com/semperfifis ... ray.html#b