How Big a Fish Finder Do I Really Need?

Is it worth the extra bucks to get a bigger fish finder?
Multiple screens at the helm
Get the biggest fishfinder you can fit on your boat. Better yet, get more than one. Courtesy Regulator

Just how big a fish finder do you need? It’s a question just about every boat-owning angler will ask themselves when they buy a new boat, and again when they upgrade their electronics. It’s really, really easy to boil down this question to a one-line answer: the biggest your boat’s helm can accommodate. Period. If you have the room, multiple fish finders are even better.

Cost Equation

Simple, right? OK, now let’s pick apart that assertion a bit. Obviously, the downside to getting a bigger fish finder is additional cost. But ask yourself: What percentage of your boat’s cost would an upsize unit amount to? A pretty good guess is 2 to 4 percent. Next question: Would you want to save 2 to 4 percent on your boat’s cost if you knew it meant you’d catch significantly fewer fish for the lifetime of the rig? Because that’s exactly what’s likely to happen.

Big-Screen Effect

What you have to remember is that you’re trying to represent a vast area of water on a comparatively minute screen. If you’re fishing in 50 feet of water and trying to compress the snapshot of that swath of H2O onto a 5-inch screen, 30-inch fish will be little more than tiny dots. Trying to spot baitfish will be like trying to spot fairy dust. Oh, and you say you’d like to see the chart plotter at the same time too? That screen just shrank again.

HD Analogy

Do you remember when you upgraded your TV to a jumbo high-definition version, put on the Nature Channel, and discovered that you could suddenly see the hairs on an ant’s leg? The difference is just as stark—and just as illuminating—with a grand-size fish-finder screen.

Easier Navigation

In case we haven’t convinced you yet, note that navigating is a lot easier with a larger screen that allows you to zoom out and still see details such as contour lines and depths. You’ll be more accurate when plotting without having to zoom in and out to find markers and channels. 

How Big Is Big?

Just how big is big enough? Different folks have different opinions, but for most serious anglers anything under 9 inches is usable only for the most basic applications. Upping the ante to 12 inches or larger will make a massive difference. The bottom line is: Bigger is always better. So, stop asking how big a fish finder you need. Instead, measure that helm station and find out just how big a fish finder you can ­possibly put on there.