Using a fish finder for trout jigging

The fish-finder has made huge leaps forward since basic sonar was created nearly 100 years ago. Today’s units are more like computers – in fact, my own recent upgrade, a Lowrance Carbon nine-inch, has dual-core processors to provide the amazing amount of information available to anglers even more quickly.

My greatest pleasure in fishing involves hunting the fish, and the fish-finder is my eyes, providing information as to what lies beneath the boat. Most of my boat fishing involves jigging for trout in fresh water less than 60 metres deep, but the techniques will translate to inshore and harbour saltwater fishing, too.

At this point I must confess to not being a technical, computer-type person, but having said that, when I see a product that will make my life (fishing) more productive, I take it on board. We anglers can never have too much information.

As mentioned, because I am not fishing deep water, I have no need for a high-powered sonar transducer, with my current Lowrance unit matched with an Airmar TM150m. I am more than happy with this medium 95-155 frequency transducer and the readings it produces. I do, however, recommend CHIRP transducers (Compressed High Intensity Radar Pulse); CHIRP basically bursts off different frequencies, giving cleaner, more defined 2D sonar images. Picking the right transducer for your style of fishing is crucial.

Use your zoom function if you think there may be fish hard on the bottom. I have caught some very large, koura-feeding fish tight on the bottom that could easily have been missed without the confirmation provided by zooming in.

Touch-screens have dramatically increased the speed and ease of navigating around different functions. I fish from an open boat, yet have no issues with rain and wet fingers. The latest Solarmax HD screens are crystal-clear in all light conditions and are not affected by polarised glasses. Make sure you have a ‘tech cloth’ handy – keeping them clean is the trick.

Use your ‘track back’. How often have you gone over fish, turned to relocate, and struggled to find them? ‘Track back’ gives you the ability to return though history, create a GPS mark, and go directly to it. This saves a lot of time and frustration.

I continually adjust my sensitivity control (gain), running it as high as possible (I do not mind a bit of clutter, most of which in the accompanying pictures is the thermocline). This enables me to see my sinker and, in the right conditions, even the three flies above it in relation to the fish. The ability to sight-fish through a screen is very exciting; not only do you feel the hook-up, you can see it, too.

Down scan, side scan and the latest 3D imaging are great tools for a more photographic-type image of structure. I have been using 3D since early April and it is a great tool when searching for smelt and trout in less than 30 metres of water. Its wide beam provides the ability to see fish in relation to structure in a 3D image, which also adds to my knowledge of where fish can hold. I love the fact that it’s possible to see which side of the boat the fish are on too, enabling me to position the boat so the situation on offer is more favourable for the skipper! Having located the fish though, I still prefer traditional sonar for the process leading to hook-up.

Surprisingly, there are no electronic charts available for the Rotorua lakes, only very inaccurate paper charts made 40 or 50 years ago. But that’s no longer a handicap. Features like C-map Genesis (formerly Insight Genesis), mean modern sounders have the ability to create extremely detailed maps which, in turn, have completely changed how I fish. The last 30 months spent creating maps have been a revelation, enabling me to see on screen what I once could only visualise roughly in my head. Using C-Map Genesis is as if the lights have been turned on.

While using a bow-mounted GPS-guided electric motor and slowly working (1/4mph) the GPS bathometric lines created by C-Map Genesis, I often find the trout move though areas I have chosen to fish at very similar depths over a day’s fishing. Drifting with the wind, but at the wrong angle, means you may only be in the strike zone for a few seconds.

Anchoring can be great when you have found the fish, but can mean long periods waiting for them to turn up. By moving and working structure and banks accurately, I’m not only hunting, I’m also gathering lots of information about the area. This includes valuable information, such as pinpointing where and why the baitfish and trout are holding in different conditions.

When looking at a C-Map Genesis map, I can see large formations and how they relate to the small piece of structure I am over. My sonar, including the down-scan/side-scan and 3D screen options, tells me when there are baitfish and trout under me; my C-Map Genesis maps explain why. This information can only increase our fishing knowledge and enhance our ability to become more successful anglers.