Naturally, we ask, and get asked a lot of questions about fish finders but with the advances in technology over the last several years, this question has to be one of the most frequently asked. Which is better, side imaging or down imaging fish finder?
The answer is anything but simple but you might be able to guess the answer. It depends.
If anyone tells you differently they just aren't informed because like a certain bait, or presentation method, the best usage is entirely dependent on what you are trying to accomplish.
Are you fishing in shallow weedy areas for Bass? Are you targeting schooling pickerel (walleye) or hoping to catch them on the transition of changing depths and structure?
I know I'm asking more questions than I'm answering here but we want to add real value to real anglers. Unless you're a tournament fisher you probably have limited time, limited money and preferred target fish. If you do an honest assessment you'll probably make your decisions about gear and accessories a lot easier.
If you can only get out once a month, and can't justify more than $200 on a unit or you do kayak fishing and need portability, you're probably going to think down imaging is best. If you fish similar areas of moderate depth but are looking to hone in on solid structure, schooling fish or track bait balls you may need the added capabilities and side imaging perspective.
So once you know yourself, your preferences and your most likely style of pursuit you'll have a lot less options because some units just aren't fit into certain uses or some budgets ... and this is a good thing. It makes life much simpler when we stop looking to find the silver bullet for fish finders that is the best. There is no best for everything fish finder... or put another way....
All fish finders have limitations
For instance, imagine you see the below presentation on your down imaging scan:
You're licking your chops at what is clearly a school at about 15 feet. Clear ... as ... day BUT
What side of the boat was it on? It was clearly activity behind your boat (another limitation of down imaging or scan is that everything you see has already happened).
So it's not about which one is better, it's about perspective
For instance, take this image shot with a combo fish finder that has both SI and DI
If you only had the SI image, you'd just see a tree. But couple that with the DI scan and you see there is much more to be seen. Not fish in this example, but easily enough that structure could have something of interest and without Down Imaging you'd never know.
So, perspective, is important. Simple as that.
Coverage is in the eye of the beholder
Another important feature is the amount of coverage provided. Several hundred feet of lateral coverage is provided off of each side with the top tier SI fish finders. Similarly several hundred feet of depth can be provided on top tier DI fish finders. So clearly if you're talking number of feet, SI seems better because it covers two sides but.... DI focused imaging provides coverage where you need it most right?
Well... as you may have figured, the answer just isn't that simple. There's no right answer at all. Coverage is only good if it's coverage where YOU want coverage.
Side imaging has wide coverage and provides incredible perspective of the area as a whole.It's optimal use is for grid pattern with chartplotting to identify good structure and contours for an area you intend to zone in on.
Down imaging has narrow coverage but if you're in the right spot that's what you need. If you're not in the right spot, you'll be staring at seaweed for hours.
Know your purpose, know your goal and the decision about what to mount on your rig becomes incredibly simple. Fishing the lake at the cottage, you could probably run DI only if you know the water. Run a new lake every trip? Might need SI to help you find the unique structure and contour changes that attract the schools.
In the end, there is no best or better or winner. There is a tool for the job and picking the right tool for the job is what separates Trophy Fishers from recreational boaters.