Side scanning sonar has been around for a few years now, and we’ve had a chance to put it through its paces. So, what’s the final decision? Should you get a side scanner, and is it worth the extra expense?

Humminbird hit the market with side scanning a few years ago, and it's been long enough that users have a wealth of side scanning experience.

Yes, no, and maybe are all valid answers. Here’s why: side scanning is going to prove incredibly helpful when you want to find structure off to the sides of your boat, in relatively shallow water. In a 20′ deep lake or bay, for example, you’ll have no trouble finding things like standing timber and protruding boulders 40′ or 50′ away. But in deep water, side scanning effectiveness drops. Take 100′ deep water, as another example. In this depth you should be able to spot items a good 200′ off to the sides, but something as large as a submerged subway car (planted for a fish reef) will usually show up on-screen as a small, wispy return. You’re covering such a large volume of water with such a small screen that even large returns show up in a mere handful of pixels. Can’t you zoom in? Of course – but then you’re limiting your view to a very small area, which defeats the entire purpose of side scanning in the first place.

This is where the “maybe” comes in. When used with deep water applications, the size of the screen has a much more dramatic impact. If you’re peeking through the depths with a seven-inch LCD, you could pass that subway car without even taking notice. But on a 12″ or 15″ screen, the return that shows up will be large enough to catch your eye.

Trees and boulders show up well, as you can see on this Lowrance unit.

In other words, side scanners provide you with a lot more utility when you have a large screen model. If you’re splitting the screen between side scan and down scan, or side scan and GPS, this becomes even more true. So – should you invest the extra cast in a side scanner? If you fish in relatively shallow waters, the answer is an unqualified “yes”. But if probing deep water is in your future, you’ll need to get that big screen model to get the best bang for your buck.