Sounders/Sonars - "Who watches the watchers"?

[hazmail]

I bought a new sounder (Lowrance colour X515c DF), and as always it's a steep learning curve. I don't think this Lawrance is as good as my old Furuno black/white, which has much better resolution, without the pretty colours??

I found this thread on another site (Australian) and found it quite helpful, and thought maybe it would be a good idea, to start a thread on the same topic here, as most of us are freshwater fishermen, where most of the posts on

Sounder Reading - Ausfish Australian Fishing Forums discuss and show pics of salt-water situations.

Knowing the vast areas of fresh water lakes/rivers there (US), coupled with the huge numbers of guys (and goils) who participate in freshwater fishing, I am thinking there should be a vast amount of knowledge stored up in some heads on here, some of which you might like to post.

I am not wanting to get into a debate on which brand is better, as we all know, basically they all work the same, just different levels of information - I am more interested in analysing what we see on the screen, weather it is Bass, Muskies, or GT's. pete

Edited October 10, 2008 by hazmail

[Kajan]

I fish coastal, most important thing is high speed reading. Lowrance and Eagle are prob best at shallow water high speed readout. Never tried Garmin though. I know many bass fishermen like humming bird, and I notice they have some fine sonars, but not for high speed, they dont' work. If you fish shallow, prob your best bet is Lowrance. But like I said, I use only depth read out both high speed and while fishing, watch my drop offs with depth instead of chart.

[hazmail]

Kajun - thank you for your reply, yours is the only one in 2 days, maybe they all want to keep their knowledge a secret!! Any information is good information.

I think you are on the money using your yours for only depth. I know if you don't have one on the boat I feel lost, not knowing what depth I'm fishing over.

Thanks again.pete

[Sonny.Barile]

Haz

I have a cheap portable unit from Humminbird. It is a Pirannahmax 10. I dont have a high speed boat so it reads great at full speed. (about 22mph) It came with a suctioncup to hold the transducer on the transom but using it that way means you are limited to slow trolling. I bought a clamp mount for the boat so it stays on at full speed. I primarily fish a saltwater river that has a deep enough channel for large barges and tugs to get through. It is tidal so at times the current can really flow fast and hard. The river is surrounded by swamp marsh for many miles so there is plenty of weeds and plant debris floating below the surface. This can make marking fish a difficult task with false readings. There is so much seaweed and mud at times it can appear that there are two bottoms for long stretches. I only use it to read depth, find droppoffs and structure (mostly humps and stationary weed beds) and to read temerature. Temp is important for migratory striper fishing. On occasion I fish in a large bay known here in Jersey as Raritan Bay. (It is the back side of the famous Sandy Hook) There I use the machine primarily for reading depth while navigating as there are plenty of sand bars that you wouldnt want to hit when at full throttle. That area is what prompted me get one. I was about 150 yards from the shore and travelling at full throttle when I decided to stop and take a look around. I looked down and saw my outboard skegg was about 2 inches off of the bottom. If I had hit a rock at speed it would have been awfully expensive. Most of my bay fishing is done in the shallows so depth and marking fish is not as important as temp while fishing there.

Sonny

[hazmail]

Sonny - when migratory striper fishing, do you motor around the channel until you get the right temperature and then start fishing??

I don't think we get 'stripers' here, looks like a real speed machine. I googled it and all I could get on google Australia, was 'strippers'!!. There is a fish here that looks similar (without the stripes) called 'Mulloway' or 'Dew' fish, which grows to similar proportions (50lb or more) great fighting fish and usually caught at night and is an excellent table fish, need a big table though. By the look of the eyes on stripers, it looks like they would be partial to a bit of night hunting too??pete

Edited October 14, 2008 by hazmail
edit text

[nickcalderone]

Hazmail,

I have used the Eagle Fishmark 480 extensively. It is "simple" by most of todays standards, but I have found it to be remarkably accurate and the settings are easy to adjust once you learn the menus. It works just fine at full speed (about 40 mph) as well as stationary or slow trolling. I have used it in fresh, salt, and brackish water (I live in coastal Alabama) and have been satisfied with the information that it is able to display...but keep in mind, the information is open to interpretation. After I purchased the units (I bought 2, one for the front, and one for the driver seat) I installed them and spent nearly two days on the water just reading the sonar. NO FISHING! Yes, it was tough. Anyway, I found that saltwater required more fine tuning than freshwater...perhaps the density of the water and salinity content. There is a crystal clear freshwater lake not far from here, so, I spent a full day just idling and trolling out there. I was able to visually see down about 30 feet, so, I could see with my eyes whatever the sonar could see. It was very accurate...for the most part. There were a few false readings, or ghost fish here and there. This happened mainly when I would glide over a tree top that had large branches jutting out. Some echo's would come back as fish arches even though I could SEE with my eyes that they were not. I was most impressed though with the ability of the unit to track a jig, dropped vertically, in 30 to 40 feet of water. I could literally see the line "move" on the side of the screen. This is great when you know exactly what depth the fish are holding. As for depth, countours, structure and bottom composition, I was able to get a fairly sharp perspective of what was below the boat, but it did take some time to learn to interpret what I was seeing. It seemed to false alot more often in salt water, although, that could have been more of an adjustment error on my part though. I think that most all of the units (except Humminbirds sidescan sonar) are basically open to your own interpretation and adjustment on your home water. The more time you spend looking at them, the more that you get a "feel" for what is down there. I wouldn't really say that I use it to find fish as much as would say that I use it to find structure and depth. On a side note, Humminbirds side scan units are absolutely amazing! A local guy here was trying his out on the same lake I fish and found a beechcraft cessna airplane on the bottom in 40 feet of water! I posted the story and the images on here a while back. It was like looking at a photograph! I had the opportunity to check one of these units out on the water in a friends boat...and I have to say, these things are far beyond anything else you have fished with. EVERYTHING is displayed with picture perfect clarity...no interpreting necessary. I was thoroughly impressed. So much so, that when I can afford one, I will purchase one. The menus were easy to navigate, and there was SO MUCH DATA. Kinda intimidating at first, but once you get the hang of it, you are "hooked".

Anyway, sorry to ramble....just wanted to add my 2 cents.

[rhahn427]

I have several Lowrances ....... my best one is the LCX 111c. It has at least equal if not better resolution than any other DF I have seen including the Furano's. It also has a wide range of colors that are instrumental in telling the bottom type as well as the species of fish that you are seeing. I fish on the Chesapeake Bay (saltwater)and there are many guys that use this and adjust the sensitivity so they can see different colors of part of a mark. This along where they are in the water column tells them what species it is. They say it is the reflection on their bladders. Sounds crazy but I've seen them do it when searching for baitfish. We'd see a school on the bottom and they'ed say they were perch. Drop a bait and perch ....... another school and he'd say spot and they were spot ........ and you could see small differences.

THe Lowrance reads accurately at the 30 MPH my boat cruises at and shows the schools of fish as well as bottom structure and water temp etc and the GPS is very accurate.

One feature I like is being able to mark a GPS waypoint by placing the cursor on a spot on the sonar readout and marking it. THis makes it much more accurate.

Yesterday we fished the shallows where we found them the day before but they were'nt there. Went back to a hump we marked on the way out and search the area and found the fish ....... had a ball on stripers 28-35" (big for the bay this time of year) for a couple of hours and left at dark with fish still on the screen .........

My Lowrance puts us on fish ......

[clamboni]

Eagle 320. Same company as Lowrance.......Not a high resolution unit but fine for shallow water. It was cheap and my other one crapped out on me so I bought it.

Anyway.......It's a good screen shot. The thick line near the bottom is the fish, it's the one that comes straight up in the middle of the screen. Just above there's a very thin line that's my lure. The vertical line is the fish coming up to the boat after he's hooked. I fish like this all winter long in water up to 25 ft. It's great, you can watch the fish move up to hit your lure. Only thing is most of the fish that you can get to move more than 2-3 ft come up and slap the lure really hard but don't get hooked.

Black crappie by the way.

red line is my lure, blue is the fish.

As far as knowing what exactly it is on the screen, the only way to know that for sure is to catch them. You can have a pretty good idea from knowing what one species is relating to on a particular day, but no sure way to know without having the fish in hand. Even the size of the marks can be decieving. Sometimes it'll pick up a big fish near the outside of the cone and only show a little mark. Or small fish will give a strong return and show up as a big mark. One thing though, once you get your unit set up properly and get a little confidence in what it's trying to tell you, TRUST IT. If it's set up right, it won't tell you something's there if it's not. My rule is that if I see fish on the screen, I assume they're the species I'm after unless proven otherwise.

Example of a 8" largemouth showing a big return.

Edited October 18, 2008 by clamboni
added info

[clamboni]

I'll update this with some more pics within the next couple of months. Most of my really good sonar screens are in late fall/winter.

[Kajan]

Clamboni, nice pics and Nice Sacalait', we have both kinds here, blanc' and black.

Yea sacalait fishn was only time I ever used graph feather. In deep water you can find structure and put jig on fish's head almost LOL.

[hazmail]

Thanks guys for your input (been away fishing), those pictures say it all, and as we are all saying, 'it's all up to interpretation' and this is where I need to put the time in. I am off chacing trout on Sunday for 4 days, so I will try and get a few screen pics, if I can get the tarnsducer to show anything ledgeable, that is. Thanks again.pete

[hazmail]

OK guys , what am I looking at here??? Are those lure shaped lines fish, and what are the blobs in the middle and top of screen. The settings are about 90% sensitivity, and the upper/lower limits are set at 6-30' in 67' of fresh water.

My past sounders (Raytheon,Furono) have shown arches as 'arches', not these 'Rapala' shaped lines - if they are fish, all I can say is they were not hungry (Trout), I was looking at this for 4 days, and caught 3 under size fish, I was starting to think I was hallucinating. Any input/theories welcome. I had more pictures but we were shaking around too much, which killed the quality.pete

[/img]

Edited October 30, 2008 by hazmail

[clamboni]

I don't use a color unit, and it's a little different reading them, different colors mean different things supposed. But......What I think I'm seeing is two things.

one is that the clutter all around the screen looks like the sensitivity is too high. You want just a speck once in a while on the screen when it's not showing fish or cover. Hard to tell though unless you're looking at a screen that's not showing so many returns. Every day on the water is different, with water color and temperature making a difference, but on my 200khz units I keep the sensitivity anywhere between 70 and 80 % about 95% of the time. These are monochrome units.

The second thing is all those lines definitely look like fish to me, they're just not near the middle of the cone. The ones from 12 to the bottom of the screen especially look fishy. The ones near the top of the screen are a little tougher to tell. With the 200khz transducer the cone isn't very wide at a depth of 8' (20 degree cone angle). So if it's only a couple feet across the cone, you're not going to show an arch, just a blob like you're seeing. If you notice, the marks toward the lower part of the screen are a little more arch shaped, as well as longer because the cone is wider and they're in it for a longer period of time.

What I like to tell people is to picture the unit telling you how far away from the transducer an object is, not necesserily how deep it is. When you see the perfect arches, say an arch that the top looks like it's 2 ft above the bottom. When the fish enters the front of the cone, it's say 20 ft away from the transducer. That's why the leading edge of the arch is at 20 ft. As the transducer moves over the fish, even though the fish isn't moving up, it's getting closer to the fish. When it's in the middle of the cone, it's 18' from the transducer, so the arch slopes upward to the middle, and shows the top of the arch at 18'. Then as you pass over, it's getting farther away so the mark slopes back downward to 20'.

When a fish just passes through the edge of the cone, there's not as much of a distance change. So the mark looks smaller and much less arch shaped. With high sensitivity settings, you can even get returns from objects that are slightly outside the cone. That may be what's happening there.

Edited October 31, 2008 by clamboni
Rearranged some things for better flow

[hazmail]

Clamboni - thanks for this, it explains a lot, I liked your analagy on the distance thing, next time I go I will try and get some more examples. I'm starting to think this sounder may have too much power for the depth I fish, which is mainly 40' and up. Thanks again .pete

[clamboni]

Pete, you mean 40' and less of water?

If you want a wider cone angle, try switching to the 50khz frequency. The 50 khz has a much wider cone angle and should show you much better arches in shallow water.

On my dual frequency Lowrance unit......hit menu, go down to sonar features, and move the cursor down to 50 khz and hit enter. You'll need to re enter your settings but once you get it set up it should be better for the shallower water. Don't forget to bring the book out on the water with you. Every time I get a new unit, i bring the book out with me and one rod with a little tiny jig. I go out and look for small fish on the screen and use the jig to catch them.

It's almost time now for me to get those great screen shots so I'll be posting some pictures up in the next few weeks.

[WAM]

Hello,

That's quite a mess that you have on the graph. I don't recall seeing anything about where you had the puck mounted?? If you are using a through hull I have seen some images similar to that if there are air pockets in the epoxy used to seat the puck. Also the hull itself can cause some issues with resolution especially if it's a metal hull. Another posibility if it is mounted on your trolling motor is feedback from the motor although that doesn't seem to show up as much unless you are running your wiring through something else. Try to make sure you have a direct conection to your starting battery. If your model has GPS just make sure you have a switch in the circuit or it will cause a constant drain on your battery. If the transducer is mounted outside and you are getting images like that I would first check the settings. Sounds to me like you are really driving the puck hard with a setting close to 80 percent. I have played with many models of the Lowrance units. I personally have the 520C and love it. I know many of the top guides around here use lowrance and most don't drive their units sensitivity that hard. What you are really doing is sending double signals down to the bottom and it will burn the puck up much faster. The default setting from the factory to "slightly" higher is more than enough to sort out what is down below without causing extra wear and tear on your equipment. I only fish freshwater however. We typically fish for spotted bass and smallmouths and have no trouble locating them in 25-60ft of water. I'm not as good as others at picking them out when they are laying on the branches of flooded timber but they show up quite well when they come off the limbs after my drop shots! Similar to the crappie pic before. You can watch your bait and actually see the fish come up and take the bait. More like a video game than fishing! One other factor can be other graph interferance. Driving the puck harder also increases this. Any other graph in the boat will do it but depending on the water depth you can actually pick up signals from other boats in the area. I wasn't aware of this until I went with a local guru. I knew I would see intermittent clutter and trash on my unit and thought I had a setting wrong but in reality when I got within 50 yards of a marina or another boat is when I randomly got the feedback. I didn't know what was causing it until he pointed it out. I hope something in my rambling will help you out.

Good Luck,

W.A.M.

Mike

[hazmail]

Clamboni, yes 40' and less of water, and yes I had the book, but spent more time reading than fishing, very fruastrating!! I thought 50hz was the high power/narrow cone and 200hz was low /wide cone?? Better check this.

Mike thanks for all that, it all helps. The transducer is transom mounted and powered directly to the starter battery, which does get interference when the o/board is running, but otherwise, with the electric minkota is pretty good.

pete

[clamboni]

OK, got a couple good shots......They're blurry as they were with my camera phone while it was dark but good enough that you can see what's going on.

Those are pics of a school of these (menhaden, or bunker, depending on where you live)

getting annhilated by a school of these.

In the first one you can see the bass coming up off the bottom. Remember that the stuff to the right happened after the stuff on the left. So if the mark is higher on the right, it's a return that's coming up.

The second one, the bait isn't that thick but you can see the bass much better coming up for them. Caught two bass from that school in about a half hour, then the sun came up and the school broke up. Really wish I was there a few hours earlier.....Talked to someone that was there earlier and he said they were there all night long.

Bonus pic..........This is the fish in the picture.......ate my jerkbait really good.

[hazmail]

Thanks CJ, this is very graphic stuff, I notice some of the 'arches' are upside down !! Seeing these, is pretty reassuring, compared to my 'Rapala' arches. Next time I see a bait ball like this, I am going to stop and see what develops, and maybe get some pictures. Nice fish too - two that size would be fun.pete

[BobP]

Haz, the 200 khz is the narrow high definition beam that concentrates the power of the sonar into the narrowest cone and shows the most detail. It is usually a 20 deg cone width (out of 360 degrees). The 60 khz beam spreads the same energy out into a wider cone that has less energy density and therefore shows less detail, but it can mark fish in deeper water (>600 ft). Most shallow water fishermen use the 200 khz beam most of the time. You need to remember that a 20 deg beam shows a circular area of the bottom that is only 7 ft in diameter in 20 ft of water. That's one reason many good fishermen use sonar mainly to discover COVER that SHOULD hold fish instead of depending on the sonar to actually FIND fish. Regarding fish shapes on sonar, you get a "hook" shape only if you pass directly over a stationary fish, as the beam passes over the fish and records its head, body and tail density. Most times, on most sonars, a fish looks like a WORM on your sonar (like in your pic!). At constant boat speed and sonar scan rate, the longer and thicker the worm, the bigger the fish. A bunch of worms is a school. Anything not connected to a bottom feature is suspected to be a fish. Maybe it's only seaweed but it's a fish until proven otherwise. Anomalous small humps on an otherwise flat, featureless bottom may also be inactive fish. There are lots of fine points about interpreting sonar images and a good source to peruse is the Tactics forum of the Bass Fishing Home Page. There are a couple of experts who often post sonar images with detailed and insightful interpretations.

[hazmail]

Thanks Bob, that is very reassuring, I sometimes wish they would make a good quality 'shallow' sonar as I would never fish in water deeper than 100' and usually it is more like 20-30' max. I will also check out that link, sounds interesting.

Sorry I have not posted any pictures lately (as promised), it has been too hot to lake fish, about 100 here all week, and in Adelaide and Melbourne it was 115 (43-44C, which is a 100 year record temp for Adelaide)), you would cook on the lakes.pete

[WannabeeFishing]

I just stumbled on this thread. I use a Lowrance LCx 26hd unit with a Navionics chip for my local lakes.

In this screen shot I ran across a school of Striped Bass or Hybrid bass (Striper and white bass cross). Both are rampant in our local lakes in north Georgia).

Although they didn't show in this shot one thing to look for are schools of bait fish. They normally will show up a single dark blob. They are important as the game fish (Stripers, Largemouth Bass, etc) will normally school under the bait fish.

Then you need to determine the appropriate depth and deploy a lure that will work that depth.

http://i272.photobucket.com/albums/jj169/wannabeefishing/IMG002141.jpg

[hazmail]

Nice shot Wanna, I have fished something like this a few times (more vertical fish pile) for no result, never thought of fishing under it though!! Must give it a try next time. thanks for your input.pete

[BobP]

I fish out of a bass boat with a Humminbird 987C sonar with mapping and sidescan capability. It's an expensive sonar but worth it to me because you gotta FIND fish before you can CATCH fish - and the 987 does that very well. I think of using sonar as two different strategies.

The first strategy: If you are cruising in 20 ft of water or less, you need to be looking for cover and bottom structure that should hold fish. You may see baitfish and you may see a thermocline in fresh water lakes. Baitfish and bass will typically be holding at or just above the thermocline, so it's good to note that depth. Continue towards shore until the bottom and that depth coincide. Find cover there and it's very likely you will also find bass. You may or may not see large fish like bass because your boat running over them often makes them shy away. But cover and scattered baitfish at the same depth = bass. In fresh or salt water, bass most often have a preference for hard bottom areas and you can find those with your sonar too if you pay attention. If all else fails - read the instructions! They will tell you how to differentiate soft and hard bottoms.

The sidescan sonar is a recent enhancement first incorporated by Humminbird, and now also by Lowrance. Few if any pro tournament fishermen will practice nowadays without one of these in their boat. Before Lowrance came out with their own sidescan units, it was funny to look at pro boats with Lowrance sponsorships and see the humongous Humminbird sidescan transducers bracketed to their transoms. They pulled away from the dock, pulled the H'bird unit out of a compartment and used it during practice. Thank goodness those poor guys can now buy a Lowrance sidescan unit! Sidescan is a very nice capability. You can idle down the center of a creek and see all the cover and structure, out to a couple of hundred feet to the left and right of the boat. You can look under docks and other shore features. You can also mark waypoints on all that cover and return to fish it later. All without running over the fish and spooking them away. Pretty neat stuff!

The second strategy for sonar is based on the dictum: find the bait and find the bass. Baitfish often live in schools for protection and with a little experience, you can take a look at shad school (they look like a cloud in the water) and tell whether it is being attacked by predators. This is like fishing for surface feeding fish but it can happen at depth and you would never find the situation without sonar. I regularly spoon jig for bass in a freshwater lake where they attack schools of shad in water as deep as 55 ft. Without sonar, I would never locate the activity and would be missing a prime opportunity for easy fish catching!

I can't say that saltwater species display all the same habits of freshwater bass but it's a good bet that most species that feed on smaller species do just the same. Find cover. Find baitfish. Catch fish.