Kg the technology in today's marine elecs has made more advances in the last decade than since the ENTIRE time period preceding it! The old days of red flashers, paper graphs & even LCRs is "popsickle sticks, skint knees & pony tails" elementary compared to what is available today. The GPS was quite an advancement for position fixing/storing but the development of side & down imaging has simply opened doors no one knew even existed before! Sidescan tech has existed in various forms since the 60s but was it essentially only used by the military because the technology didn't exist until the late 90s-early 00s to use it via a small, fixed transducer that could be easily mounted to a fishing/recreational size watercraft. Before that the transducers were packaged into a towable that was nearly the size of a small fishing boat & required crew onboard a large craft to launch, use & retrieve. (The yellow, "towed missile" looking things you've seen being used to "map" the ocean bottom in the hunt for the missing Maylasian airliner is exactly what I'm referring to!)

Like anything else, as computers evolve each year to be smaller & more powerful, those capabilities are built into new units each year. While not "the latest & greatest", the Humminbird 997Si & 1197Si units I have on my bassboat have shown me in a few short years what I NEVER knew after decades of being on my home waters of Pickwick & KY Lake. With the sides can adjusted anywhere from 75-50 ft range, thats each side so if set on 75ft left & 75ft right, you can scan a section of the lake bottom that is 150ft wide. The image is full 3d & "underwater picture like" so you know exactly what you are looking at & what is down there. You really CAN'T get that 3d image via conventional 2d imaging nor even via down imaging!

The down imaging is really more of a great compliment to side imaging than it is a great stand alone feature. (But for sure it's the best of 2d options!) On a standard red flasher depth finder a standing tree on the bottom looks like a red blip or blob. It could be a large rock, stump or pile of logs & you likely won't know for sure what it is until you drag a lure thru it & feel it out. On the old paper graphs or LCRs you can tell a tree from a rock pile & possibly even see fish suspended on the outer edges of it. With the color 2d units you can get a better idea of how thick the tree is & might even begin to see baitfish & smaller fish in the tree as well as differentiate bigger fish holding tight to the tree. With down imaging suddenly each branch, limb & fish is "painted" in your selected color to tell quite vividly what you are looking at down there. But with side scan, suddenly you can see a full 3d "picture" in vivid detail that shows the exact dimensions of the tree, how wide it is, what limbs are where, which fish is on which limb & which side of the tree it's on. You might even be able to determine what kind of tree it is!

I know this is MORE than you asked for but I said all of this to actually try & save you $ in the long run. After a few trips or a season at most, you'll WISH you had a full sidescan unit after you begin to see what's down there with a down imaging unit. Most of the guys I know who use the medium size down scan units do so on the bow as a compliment to a full on & larger side image unit they have on the console. They can scan across an area to get a feel for the general area & know what is down there & where it's all at in relation to the boats position. Then with the smaller down image on the bow they can seek out smaller, specific targets to fish. But that's impossible without first the "flyover" pass with a side image unit. Another truly neat feature of side imaging is the cursor on the screen you can move anywhere to obtain a GPS co-ord/lock on. If, while scanning a 300yd long section of lake, you see a great looking brushpile/rockpile/stump whatever & it's 60ft to your left. You can move the cursor to that target & hit a button which will lock that co-ord as a waypoint. The you can motor back over to it later in the day (or even next year) to better check that spot out & put your boat EXACTLY where you want it so you can cast to that structure. THAT is the true beauty of sidescan & it's not possible with downscan!

And let me take ths chance to say that to fully utilize sidescan you will be much happier & better prepared with the larger 9", 10"+ screens of the bigger units. With 2d & even down image units you can get by with 5" & 7" screens but they are simply to small to properly view the larger scanned areas you'll be looking at with side imaging. So if you do decide on side imaging, then save up for the larger units... You'll be glad you did!

As for the 360 imaging, that's truly great stuff but not as huge a jump over side scan as is the jump from 2d/downscan to 3d/sidescan. The technology simply takes a sidescan transducer & constantly spins it 360degs to get the image all the way around you. Unless you just like gizmos & don't mind spending the $, most weekend lure washers won't really fully utilize a 360 unit over a comparable sized sidescan.

Sorry for the 10 chapter scroll but this stuff IS truly great. I've been bass fishing since a youngster in the late 70s & this new technology has been amazing & allowed ANY angler to get on new water or see spots in their old, familiar lakes they never would've knew existed before!

To show you the difference between a 2d color image of a sunk boat vs a side image pic of the same boat, I will post pics of a sunken aluminum boat I found in a local lake back in 2009 on the very first trip out with my then new Hbird 1197Si. (I am MUCH better with it now & could blow your mind with the images I can get with it. But that boat has since been retrieved) This is the boat via a color 2d image. If you showed me that pic & asked me what it was without ever having thrown a lure on it to feel it, I would've told you it was likely a brushmat someone put out or a lay down. NO WAY would I guess a boat from just seeing that image!