Live-Sonar Angling

From Reading the Water to Targeting a Single Fish

A standard fish finder tells me: "There is a structure down there. Fish might be holding there." Live sonar, on the other hand, can tell me: "There’s the fish. It’s moving to the left. Your lure is two meters off to the side. Lift it up. Here it comes. A little more. Now!" This is a completely different form of fishing.

Of course, one could argue that this also requires experience. You have to know how to operate the device, identify fish, and present the lure correctly. That is true. But that is not the only issue. The crucial question is: "How much of the angler's actual task is being taken over by technology?" Anyone who finds a fish using traditional methods must know the water.  He has to understand the seasons, weather, water temperature, currents, food availability, depths, and underwater structures. He has to make educated guesses. He has to search. He has to make mistakes. With live sonar, this search increasingly turns into immediate target acquisition. The fish is no longer merely being sought.

It is selected on the screen.

And for me, that fundamentally changes the nature of fishing.

Video gaming with living creatures?

The comparison may be provocative—but that is precisely why I consider it apt. A living animal appears on the screen. The angler sees it moving. He sees his lure. He can react immediately and try to entice the fish to bite.

Strike. The fish is hooked. Photo. Back into the water. Next fish.

Anyone watching anglers using LiveScope will notice that they are hardly fishing in the traditional sense; instead, they spend more than 90% of their time on the water staring at the screen to locate pelagic predators. They track these fish until they pause, allowing the angler to present the lure right under their noses. This reminds me less of the classic concept of fishing and more of a video game—except the target isn't a virtual opponent, but a living animal. And this is precisely where, in my opinion, the fishing community needs to draw an ethical line. After all, a fish is not just a pixel on a screen!

In its ruling rejecting the appeal, the Federal Court addressed this point even more specifically. It noted that large spawning fish are of particular importance to fish populations. Large fish produce more eggs, possess high fertility and genetic diversity, and can be crucial for the stability of stocks. Consequently, selectively removing large individuals can alter a population's size structure. This is a decisive point.

The issue is not that every large fish caught using live sonar automatically endangers the stock. The point is that this technology enables a level of precision in targeting individual fish that was previously all but impossible. And when humans have the ability to repeatedly select the exact fish they want, we must ask ourselves what the long-term consequences will be for fish populations.

Catch-and-release doesn't automatically make things better

One argument is heard time and again: "I’m not actually keeping the fish; I take a picture and release it back." At first glance, this sounds responsible. However, catch-and-release is not a free pass. While it is a recognized management method—and even mandated in some places (including by the WWF on the Kola Peninsula)—it also entails significant responsibility.

A large fish does not become immune to harm simply because it swims away after being caught. It was hooked. It was played. It was removed from its habitat. It may have been kept out of the water for an extended period, handled, and photographed. There is certainly a need for regulation here. Practices involving catfish, in particular, are often problematic; dragging these heavy fish onto land—where gravity puts pressure on their internal organs—is something that should be stopped. Although many catfish are photographed in the water these days, the water is often too deep in the middle of a river or lake, leading anglers to tether the fish to the boat and drag them into shallower water afterward.

The debate surrounding Lake Maggiore demonstrates that this issue is no longer confined to Switzerland. As of September 26, 2025, the use of live sonar for fishing has been banned there. Italian authorities justified the move by noting, among other things, that the technology makes it possible to locate exceptionally large fish—fish that may still suffer injuries even after being released. One need not agree with every aspect of this argument, but it certainly warrants serious consideration.

The Federal Supreme Court has drawn a notable line

The ruling handed down by the Swiss Federal Supreme Court on August 26, 2025, is therefore particularly interesting. Thirty-five recreational anglers had challenged the ban on live sonar on Lake Lucerne. The Federal Supreme Court dismissed the complaint, insofar as it agreed to hear the case. The court expressly noted that the ban infringes upon the property rights of those who own such devices. At the same time, it deemed this infringement minor, as the devices can still be used for other purposes. However, the decisive factor was proportionality.

The Federal Supreme Court held that live sonar enables the targeted selection, approach, angling, and capture of individual fish. It is precisely this aspect that distinguishes the technology from methods such as trolling. Protecting the qualitative composition of fish stocks—particularly large fish that are crucial for reproduction—therefore justifies this differential treatment. This is noteworthy. The court did not simply declare that "technology is bad." Instead, it acknowledged that a specific technology alters the way in which fish can be selectively targeted.

And this is precisely the topic we need to discuss much more intensively within the fishing community.

It’s Not About Being Anti-Technology

Anyone who argues against live sonar is quickly labeled backward or hostile toward technology. I consider this nonsense. Fishing has always been shaped by technological progress: better rods, lines, and reels; artificial lures; electronic fish finders; GPS; electric motors. All of these can be beneficial. However, technological progress is not automatically an argument for actually utilizing every available technical option while fishing. The crucial question is:

Does the technology enhance our understanding of fishing—or does it increasingly replace the acts of searching, observing, and applying skill?

With live sonar, I believe that line has been crossed.

A New Inequality on the Water

There is also a social issue involved that is rarely discussed. Live sonar is not cheap. The Federal Court itself noted that such devices can cost up to around 18,000 francs. This inevitably creates a new form of inequality. Not every angler can or wants to invest several thousand francs in electronics. Some anglers fish with a simple fish finder. Others own none at all. Yet others possess state-of-the-art live sonar technology, GPS, electric motors, and a full array of digital aids.

This means that a fisher’s options are no longer determined solely by experience and knowledge of the waters, but increasingly by the financial willingness to purchase ever more technology.

This particularly affects anglers who have been successful for decades using traditional methods and have consciously decided against upgrading their gear. It also affects older, less affluent anglers who cannot afford these devices. Do we really want a fishing culture where technical equipment increasingly determines who finds and catches the big fish? Or do we want a form of fishing where knowledge, patience, powers of observation, and angling skill once again hold greater importance?

When the trophy fish becomes nothing more than social media content

I find the way these images are handled even more problematic. A large fish is located using live sonar, targeted with a cast, caught, photographed, and released. Afterward, the photo ends up on Instagram, Facebook, or YouTube. "What a monster!" "95cm pike!" "Huge perch!" "Released back!" And this is precisely where I feel some anglers lack self-reflection. If we know that large spawning fish are ecologically invaluable, why do I need to publicly show that I specifically sought out and caught them using technology? Why should the next angler know where and how to find these fish?

And above all: Why must an animal caught in this way be turned into "trophy content"?

Personally, I would go so far as to say: Anyone using live sonar to specifically locate and catch trophy fish should think very carefully about whether they ought to publicly showcase those catches at all. Not only because—as previously mentioned—catching fish with live sonar is hardly a feat of magic, but also because fish caught this way shouldn't become social media content in the first place. I find it even more baffling that anglers showcase these fish even in situations where pure catch-and-release isn't legally permitted. Doing so inevitably exposes one to criticism from opponents of angling. Provoking such conflicts is downright foolish.

And what about the use in fly fishing?

For me, the contradiction is particularly stark when it comes to fly fishing. Fly fishing thrives on observation. On reading the water. It is about recognizing insect activity. About presentation. About casting feel. About experience. About the ability to locate and target a fish in the first place—often under difficult conditions. Anyone who takes this philosophy seriously should ask themselves what happens when a fish is first located on a high-resolution screen and the fly is then precisely placed in front of it. Of course, one can still fish in a technically demanding way using this method.

But being technically demanding does not automatically mean being demanding from an angling perspective.

For me, therefore, live sonar runs fundamentally counter to the spirit of classic fly fishing. Presenting a fly by sight to a rising or cruising fish is something entirely different from electronically locating a fish and placing the fly right in front of its mouth until it snaps.

The former requires the angler to read the fish and its behavior. The latter requires, first and foremost, finding the fish on the screen.

The bans are no longer just theoretical

Furthermore, developments show that this discussion is no longer hypothetical. In Switzerland, Obwalden became the first canton to ban real-time sonar, effective January 1, 2023. A similar ban has been in effect on Lake Lucerne since September 1, 2023. The regulation has since been adopted for Lake Seelisberg as well; the use of such live-sonar transducers has been prohibited there since December 2024. A fishing ban has also applied to Lake Maggiore since September 2025. Bans are now in place at Sihlsee and Sarnersee, too. And this trend is not limited to Switzerland: the use of LiveScope and comparable live-sonar systems has been banned on Sweden’s Lake Ivösjön since January 2025, with a similar ban in effect on Lake Uvasjön since April 2026. In Germany, the Middle Franconia district and the Schleswig-Holstein state association have followed suit with bans. At Lake Bled in Slovenia and Lake Centro Cadore in northern Italy, the use of all fish finders has been prohibited—likely to prevent the deployment of concealed live-sonar technology. Major tournament organizers in the US (such as the NPFL or Texas Outlaws) have also completely banned these systems, while others (like B.A.S.S.) have severely restricted their use. This trend is likely to continue, and it is only a matter of time before it extends to all inland waters.

These are not demands made by opponents of technology; they are concrete fishing regulations demonstrating that authorities and water managers are now taking the issue of selective fishing using real-time sonar seriously.

Perhaps we need to reframe the question.

The question shouldn't be: "How much technology can fishing tolerate?"

The better question is: "How much technology are we willing to allow in fishing before we change its very nature?"

A fish finder that shows me the depth and structure of the water helps me understand it. However, live sonar, which allows me to locate, track, and target a single fish in real time, changes the relationship between angler and prey.  And that's precisely where I draw the line. I don't want to fish in a world where the screen tells me which fish to catch next. I want to find the fish because I understand the water. I don't want to select it on a screen. I don't want to track it like a target. And I certainly don't want the trophy spawning fish to become a trophy for an electronic search system and then a social media image.

Fishing should be more than just catching again.

Perhaps that's the crux of the whole discussion. Fishing is more than just catching. It's observing a body of water, reading the weather and the water, knowing the seasons, recognizing structures, patience, mistakes, experience, chance. And yes – failure, too. Because that's exactly what fishing is all about: You never know with absolute certainty whether there's actually a big fish under the boat. You have to believe in it. You have to search. You have to learn. Sometimes you have to go home empty-handed.

If we ever reach a point where a screen shows us in real time which fish is down there, where the bait needs to go, and when the fish strikes, then we will have achieved an impressive technological feat. But we may have lost something else in the process.

Fishing itself.

And that's why I'm not against fish finders. I'm against the moment a tool becomes a target acquisition system. Because there's a line between "I read the water" and "I see my prey on the screen."

For me, live sonar while fishing is on the wrong side of that line.