Question about what I am seeing on graph

[slickwater]

I was wondering if you could look at the photos I posted in the gallery of snapshots of my humminbird when I was out salmon fishing last time. Is the first one clutter or bait? And the third on, is it bait or small fish on top?

Also how high of a sensitivity should I be using?

Edited July 29, 2009 by GLF
added images

[j1musser]

I would have to say clutter on #1 and small fish are pretty much baitfish, perch rather than minnows it looks like in #3.

As far as sensitivity it depends on the unit. Obviously not so sensitive that the screen is full of clutter but u should pick up decent hooks like #3 bottom. U can usually adjust it to barely pick up the thermocline if it is well developed. Sometimes adjusting the speed of the screen can help get the image ur shooting for too.

[pulpfishin]

looks likes you're picking up the thermocline on #2 and #3 at about 35-39 ft. We've been marking it there also the last couple weeks. #1 looks like clutter, #2 looks like baitfish or something a little larger, depends on the size and how spread out the baitfish are, and #3 looks like you are marking fish. Keep a good eye on those large marks, we have caught fish the last two times out by dropping rigger baits right on the marks and slowing the boat way down. Man is that fun!

[Fishwhisperer]

It would appear if the sensitivity is is set a bit too high? Not sure if that is the thermocline, in picks 2&3, either. Most units, that I have seen, have a gradual color change w/ the thermocline. The marks that you refer to would appear to be clutter. With limited experience with that particular unit, I'm sure that I could be wrong. The important part is that you have the ability to mark fish.

[slickwater]

if the thermocline is in the 30's then why would 56 degrees be at 80 feet down.and surface was in the low 60's.

[LongLine]

Thermocline is not in 30"s. It is a band of water 5-10 ft thick where temp changes rapidly. High end 53-54F, then drops rapidly as you lower the ball just a little. Low end may go as low as 39 but usualy 42-43F. IE It may be 70 on top all the way to 25 Ft down, then from 15 Ft to 60 Ft, it slowly drops to 54, then from 60 to 65 it drops from 54F to 43F. The 60-65 Ft range is the thermocline. I doubt that your unit is picking up the thermocline. Blue splotches could be interference but I'd more likely suspect clumps of fleas, seaweed, etc. Straight lines on your pics could be weights, probes, releases.

[Fishwhisperer]

if the thermocline is in the 30's then why would 56 degrees be at 80 feet down.and surface was in the low 60's.

That was along my thoughts. It would appear that one rigger is 80' down? How many other riggers did you have down and at what depth? Some times, if you run the bait close to the ball, the graph will mark the lure (bait) too. One other explanation for the marks (lines) in the 30's, is the graph is picking up the DR cable.

[slickwater]

In picture #3 you can see all 4 riggers.

[cary mac]

picture 3 seems to be marking your riggers. is your unit on 2oo or 50 hz's.

[slickwater]

It is on both.

[cary mac]

the smaller stuff around 40 ft is bait fish the larger curves are what your looking for drop your riggers down to run just above the curves and if the fish so desire FISH ON

[salmonquest]

The true question is where were you when you picked up screens 2 and 4

I don't have much experience with this but my $.02 would be that you are definately picking up some solid clutter at 30. I know when you are diving there is a barrier between the layers of water that causes you to feel an immediate change in temp as you move through the water column. I'm sure this alters the temp of the water and above and below this mark making a gradual change. My guess would be clutter collects here causing the marks on the graph. Probably attracting baitfish etc.

I would say the light blue specks would be mostly clutter I know I adjust my gain until I'm picking up a lot of clutter and then back it off until I can see pretty clearly. I would guess screen 3 contains small salmon or larger fish such as perch etc.. I think Keating also mentions something about fish that are on the edge of the cone or moving in or out producing a different image other than the standard hook.

[JoeMan]

Rick, I field test for Humminbird so I sent your screenshots in to the Quality Techs at Humminbird to get their feedback. They said that it does not appear to be interference, most likely you are marking smaller fish up above the larger salmon arches on the bottom. I noticed that you have quite a bit of red on your bottom contours. The red indicates a strong signal return. Picture #3 show some red on the smaller fish at 20-40ft. Those are definitely fish you are marking. Good fishing and great pictures!

[slickwater]

Now what can I do to get rid of the interference when I am going more than 6mph. The screen just goes full of interference and I can't see anything. But it still reads the depth.