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Technology is advancing at a terrific rate and impacts nearly every aspect of your life, even something as simple as fishing. If you’re someone that frequently fishes from the shore or from a Kayak, you may have looked on at people in bigger boats with a touch of jealousy. Having a bigger boat means you may have a big advantage when it comes to locating fish, this advantage is, of course, a fish finder. However, advances in technology and readily available smartphones mean that portable fish finders are becoming increasingly popular. So, do portable fish finders work?

These convenient fish finders claim to be able to tell you a range of information, from depth and water temperatures to fish locations and movement. All you need to do is connect the fish finder to your phone, cast it out and wait for a wealth of information to be updated on your phone screen. All of this sounds amazing, but do these portable fish finders actually work and are they worth the expense? Within this article, we’ll take an in-depth look at this technology allowing you to decide for yourself if it’s something you’d like to invest in. We’ve used the Deeper PRO Plus Smart Sonar for our testing, there are of course many models available, but we’ve been very happy with the results of this model. You can find this model here


So the first question to answer is, do portable fish finders work? The answer is a resounding YES, they work very well in our testing and experience. We’ve managed to accurately gauge the depth of the water, locate shoals of fish and individual fish swimming around, as well as record the temperature of the water.

If that doesn’t convince you, here are a few more features that may sway you:

  • Wi-fi connectivity, no wires required
  • No internet data usage required when in use
  • Compatible with most phones including Android and iOS
  • Suitable for a range of fishing styles, including kayaking, bank, river, pier and more
  • Suitable for salt water and fresh water environments
  • Fantastic operating range up to 300ft
  • Accurate depth mapping up to 260ft.

There’s no doubt in my mind that these devices tick all the boxes in terms of functionality and performance, but that’s not to say that there aren’t some quirks and challenges posed when using them. Overall though, I would say that investing in one of these devices might just change the way you fish forever. Regardless if you prefer salt water, fresh water or ice fishing, these devices work in a range of fishing environments.

Setting Up a Portable Fish Finder

Setting up a fish finder is relatively straightforward as long as you have everything you need to hand. The device itself only really needs a smartphone to pair it with to get started, either an iOS or Android device will do the trick, the smartphone acts as the fish finder screen. So if you don’t have a smartphone, then you might want to reconsider buying a portable fishing finder unless you want to pay for both. As well as a smartphone, I would recommend a couple of other items to make your life easier and possibly safer.

It’s well worth investing in a waterproof and buoyant overboard case for your phone, the last thing you’ll want to do is lose your phone over the side of your Kayak, or off the end of the pier while you’re checking out the fish finder. Even if your phone is waterproof, it can still sink, so buying a case that floats is a must have. They only cost a few dollars and could save you losing your precious phone.

If you don’t already have one, you’ll need an extra fishing rod and reel. This will be used to cast the fish finder out to your desired location and for retrieving it when you’re finished. If you’ve been fishing for a while, you probably have several spare rods lying around, if you don’t, now’s the perfect the perfect time to invest in one. You’ll also need some heavy duty fishing line and clip to attach the portable fish finder to the line.

Minor Complaints

These fish finders can have some minor niggles that can cause a certain amount of frustration, they can be annoying, but in my opinion, they aren’t deal breakers and I still enjoyed using the device. My biggest complaint was that the temperature readings were not always accurate or consistent, with significant variations with each cast and differences between the manually verified temperature and what the fish finder was reporting. These differences were not necessarily massive, but they were enough to potentially cause an issue, depending on what species of fish you were trying to catch.

The other annoyance I encountered is that after casting the sonar would frequently lose contact with the phone and would require a restart of the phone’s application to pick the connection back up again. I’m not sure if the shock of hitting the water caused the disconnect or if it was due being temporarily submerged in water, but it happened nearly 50% of the time. Closing the application and restarting it only took a few seconds, but it was still irritating. I think it could be prevented with better shock insulation or if the phone application automatically tried to reconnect if the signal was lost.

Even with these two issues I still think it’s a great buy.

Portable Fish Finder Pros and Cons

It’s time to tackle what’s good, what’s bad and what might cause an issue with these innovative devices. Like just about everything else in the world, there are some great features about these fish finders as well as some drawbacks, how serious these are and whether or not they are a deal breaker is a decision you’ll need to make. We also think there is one thing that could potentially be catastrophic but can be avoided with some forethought and by choosing the right gear.

Pros: You can use a fish finder without the expense of a boat. For a fraction of the cost and upkeep of a boat, you can use a fishing finder that actually works from the shore. It’ll tell you nearly everything you could possibly want, from depth to temperature to where the fish are and where they’re moving to. You can now tell whether or not you’re fishing in spots with no fish, which is amazing and can really take your fishing to the next level. This has the potential for being a significant game-changer for anglers.

Cons: Even though they are much cheaper than owning a boat, they are not cheap by any means. The one we used for this article is at the lower end of the cost spectrum at about $200, the price goes up from there. There’s also the two little niggling traits I’ve already talked about, which are the constant disconnects after casting and the temperature variations. You’ll also need to charge the devices regularly, but each charge should last around 10 hours, which is probably more than enough for most people.

As well as the cons listed above, we think there are a couple of other issues that have the potential for ruining your day, even though we didn’t experience them ourselves. I’m sure we’ve all lost gear before on a cast, whether that’s due to a snapped line or getting tackle wrapped around a tree branch, it’s happened to us all. Now imagine that happening with a $200 spinner on the end of your line, it’s almost nightmare material. So, if you want to avoid having to swim after your fish finder or climb an oak tree to retrieve it from a branch, you’ll need to be extra careful of your surroundings and where you’re casting. I would also strongly recommend using a very strong fishing line, you don’t need to worry about how visibly it is or any of that other stuff, go as strong as you can.

How Do Portable Fishing Finders Work?

Fishfinders use the same technology as military sonar which in itself was inspired by the way dolphins and other marine animals navigate. Essentially an electrical signal is turned into a sound wave by something called a transducer, this transducer is also known as a hydrophone. This sound wave propagates through the water and will be distorted or bounced back when it encounters something solid, such as a rock, fish or the bottom. These reflected sound waves bounce back to the water’s surface where they are picked up by the fish finder.

The fish finder can then use these reflective sound waves to build up a picture of what’s happening under the water’s surface, this, in turn, is displayed on the LCD screen of the fish finder or in the case of a portable version, it’s transmitted to your phone to be shown on your phone’s screen. Differing sizes and consistencies of objects will show different telemetry on the screen, which is how we can differentiate between a fish and a rock. The scanning of the water can happen very quickly, so it’s possible to spot when fishing is moving and in what direction, which can increase your chances of success by a huge amount.

Do Portable Fish Finders Work: Conclusion

When these portable fish finders were first released, I was a bit dubious as to how effective they would be, so I waited for a few years to see how the technology progressed. In my opinion, we’re now at a point where portable fish finders are just as effective as any other fish finder, and the price has come down massively in the last few years, they are now much more affordable than they were even a few years ago. When I bought my the portable fish finder, it set me back by about $200, but over the months of using it, I would say it was definitely worth the investment. If you’re on the fence about buying one of these products, I can hand on heart recommend them for anyone that fishes from the shore or a Kayak. As I said before, it’s definitely worthwhile using a heavy-duty line for the fish finder, you really don’t want to lose it on the first case. Buying some $20 braided line is a drop in the ocean compared to losing the whole gadget, so it should be part of your purchase.