Wayne P.

Definately ---- 898c SI The 958c is a dual frequency 83/200 kHz regular sonar unit and the 898c SI does the same and has Side Imaging and Down Imaging too.

If you paddle your canoe, you may want a whole setup that includes power. http://store.humminbird.com/products/356812?product_id=9a227e41f7c7b06723b944d951b4293a There are versions like that one with more sofisticated units--refer to the Humminbird web site.

The Humminbird PiranhaMAX 160 is quite basic and is similar to the discontinued Eagle Cuda 300 in the same price range--but with a lower resolution display. Like most stuff, you get what you pay for. Any sonar unit is better than none at all.

For a used one, you should be looking for one that works and has all the parts. Some older ones don't have parts available any more such as the transducer and power cord.

What the first image represents is I was checking the creek channel on the left side (darker area) because the main lake water temp was 89-89 degrees and there had been a heavy rain. I was looking for shad and bass that may have moved to the cooler water. In the middle of the right side there is a gray blob which is a school of shad next to a stump (bright white dot). At the top of the image and in the creek channel are bass (the white streaks). I caught two of the bass after taking the screen shot. If had been in the creek channel following it with regular sonar or Down Imaging, I would have scared the fish and not even known they were there. I duplicated that same senario several times in that area. I was using the 50' range setting to have the needed bottom coverage for what I was doing and have it short enough to recognize fish. The unit can be set to display up to 360' on each side, but that makes stuff look a lot smaller on the display. My point for posting the picture is the Side Imaging technology will allow you to see horizontally to display what is in the area even in shallow depths. The display is on my bow and the transducer is on the trolling motor. The second image is with my console display and the transducer on the transom.

Another example of Side Imaging, You can keep up with creek channel changes of direction and not wander all over tying to find it with 2D or DI.

This is why. How much bottom coverage will you get with regular sonar or Down Imaging at this depth?

A membor of the pike family, either sauger or walleye.

Traditional Humminbird units use 200 kHz with a -10 db spec cone angle of 20 degrees and 83 kHz with a -10 db spec cone angle of 60 degrees. The actual coverage is a lot more at weaker sound strengths. The Imaging technology uses a sonar pulse that is very thin front to back and wide to the sides. The Down Imaging units have 455 kHz and 800 kHz plus 455/200 kHz regular sonar The DI 455 kHz spec coverage at -10 db is 75 degrees and the 800 kHz spec coverage at -10 db is 45 degrees The cone angle of the 455 kHz is 16 degrees and the 200 kHz is 25 degrees for some of those models The Side Imaging units in the Side Imaging function cover 180 degrees with the 455 kHz and about 60 degrees with the 800 kHz. They also have 83/200 kHz traditional sonar. There are two 858 models--858c Combo and 858c DI Combo refer to the coverage for each frequency.

The unit you have is a limited edition special sale model, BUT it has the highest display resolution in the industry for that size unit. Color would be your best improvement for that type unit. More power would be an improvement also. In the Humminbird 500 series, the 597ci HD DI Combo unit is the top of the line for what you have. In the more advanced data sharing models (700, 800, 900, 1100 series), the 1158c DI Combo is the top dog in the DI models. Your budget will determine how "advanced" you can go. A Humminbird Side Imaging unit will give you more information, BUT the DI images they produce are not as sharp as the DI units produce. The SI units use software to create the DI image using the two SI crystals. The DI units have a dedicated DI crystal. Every sonar unit made by any company will show you fish and bottom contours. You have to learn how to operate them and interpret what they show. I know some that have the top of the line imaging systems by Lowrance or Humminbird and don't take the time to learn how to use that technology--they just use them to get the depth. If you cannot find fish or structure with what you have, spending more for a more advanced unit won't do you any good. If you cannot get your DI unit to give you images similar to this of a river channel with bridge supports and fish from a Humminbird DI unit ; PRACTICE-PRACTICE-PRACTICE

Read my first post today again. As far as the total height, you start with the position described in the installation instructions. Re-read your transducer installation instructions and pay attention to the diagrams and measurements. If you don't have them: http://store.humminbird.com/media/document/M_XNT_ALL.pdf Yes, the Default settings.

The unit will perform very well with the factory settings. You just need to install the transducer correctly for the best performance for your hull. The 15" suggestion is for inboard type boats where the propeller is forward of the transom.

That looks good as far a hull smoothness. A better location is where it looks like one has been before to the right of the trailer bunk. Still put a little downward tilt on trailing end of the transducer. The Humminbird transom transducers are not as hydrodynamic as the Lowrance torpedo shaped ones are.

Does the unit perform properly at idle speed?

You didn't do the photo that shows some of the hull bottom, What is forward of the transducer has a bearing on performance. What boat brand and model is it?

The number one installation criteria is the transducer face has to have a smooth non-aerated water flow across face work properly all the time. If you send me two pictures of your transducer installation; one from the side and the other straight behind it from a low angle so I can see some of the hull bottom. I can critique it. Angle could be an issue, hull location can be an issue too. purdum43@aol.com

My .04 , Side Imaging or Structure Scan is a lot more useful in shallow water than Down Imaging/ Down Scan or regular 2D sonar because of the coverage it has. The shallower the water is the more beneficial it is. The Humminbird Side Imaging as better horizontal coverage that Lowrance Structure Scan since it covers from the water's surface to past vertical under the transducer. In 2' of water you can see horizontally as far as you have the SI Range set--up to 360' on both sides. That will allow you to fish bottom features that hold fish and not have your boat above those features to know where they are. This is an example I have posted before showing a creek channel on the right (dark band) that has a school of shad ( light gray blob) next to a stump (bright white spot) and bass (white streaks) that had moved up the creek after a summer heavy rain due to the cooler water. I caught a couple the bass. Note the water depth. I didn't have to be above that creek and scare the fish to know where it was. The amount of bottom coverage with regular sonar or Down Imaging would be just a few inches at that depth.

You can get a general idea of their location by looking at a land topo map and follow the blue line from a creek intersection to the end as the elevation increases. This site will allow you to switch between a satellite photo and a topo map if the lake is new enough to have a USGS survey before the lake was formed. http://mapper.acme.com/ I use this site to make my own lake contour maps for locations that don't have lake structure maps. I print the satellite map on plain paper, and the topo on clear translucent paper and lay the clear over the plain to get a lake structure map.

http://www.stren.com/prod.php?k=124634&u=scbfs

I think I saw a spring yesterday near a school of bass, but I got so involved with catching that I didn't take a screen shot of it. I'll check the next time I am there to see if it really was a spring.

Check the wires to make sure mice have not eaten the insulation off of them. You don't want it to keep tripping the circuit breaker or to catch on fire from electrical shorts. The boat looks in good shape and the trolling motor is one of the best ones ever made-it has 56# of thrust on high 24V setting.

My avatar. Not because it is my favorite, it's because it is the fish's favorite. I just give them what they want.

What works the best is doing both at the same time with a drop shot hook above a shakey head. Sometimes the fish takes the dropshot and sometimes they take the jig. Docks, road rip-rap, bridge pilings and river channel ledges.

No, I haven't been anywhere that has submerged springs. It should show up on sonar due to the water density change though if you had the sensitivity setting high enough.

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