Once upon a time, finding the fish was an art, a legend, or just plain luck. These days we have technology on our side.

Now you can spend your time fishing, not guessing. We carry a huge range of quality fish finders, so you can stop donating bait to the depths below, and haul those beauties onto your boat!

Here are a few tips for selecting a fishfinder, from one of our expert staff.

Selecting the correct fishfinder unit may seem daunting, and there’s a lot of features and names being used in the marketing. But in reality, there’s a few key features that distinguish actual performance. Then it’s up to you to determine what additional features you’d like based on the type of fishing you do, how often you do it, and the budget you have too. This guide will help you understand the technical aspects of what to consider.

FIRSTLY, HOW DOES IT WORK?

All fishfinders operate as echo sounders, which is a form of active sonar. It’s not too dissimilar to how submarines find other submarines underwater, but here we’re using it to get you on the fish! An electrical signal is sent from your fishfinder to your transducer, which converts it into an acoustic pulse. It is actually a sound wave, but several times higher than the limits of average human hearing (of around 20kHz). Just like yelling “coooeeee” from the side of a mountain, the fishfinder can then “hear” the echo.

The sound waves from the transducer emit in a beam fashion. It’s not all that different from floodlights vs spotlights on a car. The spotlights might be able to see further, but floodlights will light up a wider portion of the road. Of course the higher the transducer power, the further you’ll be able to “see” too. Just as objects on the road would create a shadow, a similar thing happens underwater. Anything with a different density than regular seawater (such as a fish’s swim bladder) will reflect back sound waves at the transducer. The complex task of the “imaging” all that data into a sophisticated display is then up to the individual fishfinder. The technology and features doing this is what separates fishfinders from each other, even if they have the same frequency transducers.

Of course that’s a rather simple explanation of the technology at its core, but it gives you a rough concept of how the technology works.

IT IS ACTUALLY A SOUND WAVE, BUT SEVERAL TIMES HIGHER THAN THE LIMITS OF AVERAGE HUMAN HEARING

THAT’S ALL GREAT BUT HOW DOES IT HELP ME FIND THE FISH?

There are a few questions that need to be asked to help with selection.

1. WHAT WATER DEPTH DO YOU FISH IN?

Using a fishfinder in a lake is quite different to using it for game fishing in open water. You see, in order to decipher what’s what, the frequency needs to be just right. A higher frequency sound provides more information back to the fishfinder, but can’t penetrate the same water depth without boosting power significantly.

If you’re fishing on a lake (or other shallow water), say 100m or less, you have the luxury of using a higher frequency (circa 200kHz). If you’re headed to the open water or fishing in >100m deep water, lower frequencies closer to 50kHz will work better. Of course most units using typical single-frequency sonar have selectable frequency ranges to work in various different environments.

What about CHIRP? CHIRP is the latest in high-quality imaging technology, which stands for Compressed High-Intensity Radar Pulse. Unlike traditional sonar technology, they emit a multitude of frequencies at the same time (rather than a specific frequency). This provides even more clarity to the returned information. CHIRP has rapidly enabled even greater clarity of imaging, previously impossible. See diagram above.

Many manufacturers are now using multiples of this technology together to provide unprecedented information. Now it’s possible for a single model to provide you with fish depth, length estimation, water depth, sea-floor composition, and more, all bundled into a single unit!

CHIRP HAS RAPIDLY ENABLED EVEN GREATER CLARITY OF IMAGING, PREVIOUSLY IMPOSSIBLE

2. WHAT ELSE ARE YOU LOOKING FOR?

Returning to your favourite fishing spot, attaching a larger screen, or specific functionality, are all part of your unique requirements. Here’s a few features to consider.

– Down Imaging

This uses a very focused beam to display images of structure. It’s a method of gaining even greater resolution and imaging, which makes novice use of a fishfinder even easier.

– Screen Size & Type

This is fairly straight forward (nobody likes to watch the footy on a small screen if they have a large screen as an option!). Larger screens will generally cost more, but will allow greater amounts of information to be displayed at the same time. The type of screen is also important. Depending on your boat, visibility in full sun (especially if it’s a tinnie) is critical. Most will feature ultra-bright sun-viewable displays, also with anti-fog properties.

– Built-In GPS

Returning to your favourite locations has never been easier. A built-in GPS means one-less screen at the helm to review.

– Expansion

Some models feature monitor outputs (to connect to any screen via HDMI), and others allow interfacing with certain entertainment systems for even greater flexibility and control. Network interconnectivity is a great feature for larger boats, especially with dual helm setups.

– WiFi Integration

The precise features will depend on the model of fishfinder, but WiFi extension is very powerful. This generally means that you can install an app on your smartphone or tablet, then use it as a fully featured controller for your fishfinder.

3. WHAT BUDGET DO YOU HAVE?

Chances are, if you’re purchasing your own fishfinder, it’s not going into a 100ft yacht and budget is at least a consideration for you. While there’s no simple scale, starting with the essential features (such as water depth) and moving up to less essential features (such as expansion) as your budget allows, is a great way to go. Most critical features first, luxuries last. That way you’ll get the most fishfinder for your budget.

STILL UNSURE?

If you don’t feel you can decide on a fishfinder, or would like to chat to a knowledgeable person about it, drop in to your local RTM store. They’ll be glad to help you determine which fishfinder is most suited to your particular fishing adventures.