Installing a Fish Finder: Complete Guide

You finally purchased a fish finder and are ready to hit the water and find those monsters. But first - how do you properly mount it?

Last updated: June 24, 2024

By: Jon Stewart

Fishing gear: ✅

Fishing boat: ✅

Fishing license: ✅

Fish finder: ✅

Ready to hit the water: ❌ Wait - how the heck do I install this fish finder and get it working properly?

You’ve come to the right place!

A solid fish finder is one of the most beneficial upgrades any vessel can have. A fish finder will allow you to find fish, food sources, and identify fish movement patterns. You’ll actually become a smart angler from the observations you’ll piece together from a fish finder.

Not only do fish finders help you locate where fish are, but they also add a degree of safety to your fishing experience. Knowing what depth your boat is at and what is below it can impact how and where you operate your boat or kayak.

However, to get the best performance out of a fish finder, it must be installed (the right way) for it to work properly. Having a state-of-the-art fish finder that is not installed correctly will leave you with a pretty expensive headache - and time wasted out on the water.

No fisherman wants that!

Therefore, taking the time to thoroughly study your fish finder and how it will be installed is critical to maximizing the performance of any unit.

Regardless of the type of fish finder or boat you have, we’ll cover everything you need to know in terms of the installation process so that when you’re out on the water, you’ll find - and catch - much more fish.

Let’s dive in! 👇

Fish Finder Installation Main Takeaways

Type of Mounts 🛠

There are a variety of different mounts available for fish finders. Different mounts are convenient for specific mounting locations as well as the type of vessel you have.

No matter what route you decide to go for your installation, it is crucial that you pick the one that is best for how you intend to operate the boat and fish from it. A fish finder that is utterly unusable from the place you will be fishing in the boat will not help you make decisions about where to take the boat or cast.

However, one that is in your way will only cause frustration until you break it. Therefore, it is essential that you consider how you intend to fish from the boat and make an appropriate decision about how to go about mounting it.

Flush-Mounting: What it is, How it works 📖

Flush mounting consists of placing the head unit inside a console so that the screen lays flat against the structure that it is mounted on. Think of this as a flat-screen TV against a wall. The aesthetics and proper use of space of a flush-mounted fish finder are far superior to any other method. 

However, flush mounting is also one of the more uncommon ways of mounting a fish finder. This is partly due to the lack of space to place a fish finder in most boats. Higher-end boats that have center consoles or bridges that have large consoles are far more likely to have this sort of mounting system in place. 

Another challenge with flush mounting, specifically with bass fishing, is the requirement for an ample flat space in front of you to mount the head unit too. Most fishing requires you to be able to have direct access to the water and limits the amount of available space to flush mount a fish finder too. Bass boats typically always come to a point for precisely this reason and leave only the deck floor for potential flush mounts. 

Binnacle Mounting 👇

Binnacle mounting is made of a cradle that is mounted to the floor or gunnel of the boat. The head unit is then placed into the cradle and secured by tension knobs on either side.

Binnacle mounts allow for the head unit to be adjusted to optimize the screen’s visibility relative to the fisherman and affords plenty of room for cables and cords to come out the backside. This is the most common way to mount a fish finder. 

Though, as with anything, binnacle mounts also have their challenges. The primary struggle with a binnacle mount is the unit being fixed to one location and often exposed to various elements of fishing. Rain, vegetation, stray casts, and kids all pose a threat to a binnacle-mounted fish finder’s cables and screens. That’s right - even bad casts can pose a problem, so it’s good to brush up on proper casting techniques if need be.

Mounting a Fish Finder to a Kayak 🛶

One thing that many kayak fish finders employ that is only now being leveraged in other areas of the fishing world is RAM mounts. These mounts utilize a ball-and-socket approach to mounting fish finders. This allows for minor adjustments to be made as well as more expensive units to be easily removed from a boat that will be unattended. 

Ensuring your kayak is equipped for fishing will allow you to fish with relative ease while simultaneously taking in the information you need to guide your casts properly. This can be in a binnacle mount, an impermanent mount, flush mounting on the floor, or on a RAM mount off to the side. It will be highly dependent on the type of kayak you have and the style of fish finder you intend to employ.

Where Should a Fish Finder Be Mounted? 🔍

There are two primary ways that a fish finder should be used. These two uses also correspond to where they should be mounted.

Firstly, fish finders are navigational instruments. This requires the fish finder to be mounted by the steering wheel or in the cockpit of the boat. This allows the operator to judge the depth of the water, the distance and direction they are traveling, and make decisions based on the information the fish finder is providing. 

Secondly, a fish finder is for finding fish so they can be caught by a fisherman. Though this seems obvious, the amount of data that is available on most modern-day fish finders can be highly confusing. Still, this doesn’t change the fact that the only other place a fish finder should be used is where you will actually be fishing. This can be in the back of a boat if you are trolling for tuna, halibut, or trout or in the front if you are bass fishing. Other fishermen that focus on crappie or walleye may want the fish finder to be mounted in the middle of the boat where they sit. 

The majority of high-end fishing kayaks will always have the fish finder mounted in the center, well out of the way from anything that could damage it. However, they are still within plain sight of the fisherman. Kayaks have the distinct advantage of being able to be used for both fishing and navigation when underway.

Ultimately, mounting the fish finder is up to how you plan on fishing. No matter what your target species is, you will always return to the two functions of a fish finder; navigation and fishing. Placing your fish finder in the correct place will always hinge on those two uses. 

How to Mount a Transducer ⚙️

Mounting a transducer can be done in three ways. First, the most common way to mount a transducer is on the transom. Almost all fish finders will come with a bracket that can be screwed onto your transom, which holds the transducer. These will typically “break away” if the transducer impacts something in the water to save you from having to replace it. 

The next way to mount your transducer is to go through the hull. This involves gluing the transducer in such a way that no air is allowed between the transducer and the hull. This allows the transducer to see through the hull of the boat and into the water. Mounting through the hull keeps your transducer safe from debris, but the installation process is much more challenging to do correctly. 

Lastly, most trolling motors for kayaks and other boats often have transducers mounted in the head. These trolling motors almost always demand you buy the fish finder that goes along with them. However, they are also typically top-of-the-line models that will yield some of the best results. If you can get a trolling motor that marries with your fish finder, that is the ideal placement for your transducer. 

Tools Required 🧰

Mounting a fish finder can seem daunting, but it doesn’t take that much in terms of tooling. In fact, mounting a fish finder generally requires the same tools as mounting a trolling motor.

You will need a screwdriver set, needle nose pliers with wire cutters, a drill, and drill bits to be able to install the fish finder successfully. While there are other tools that you can use to make your life easier, they are far from required. 

The majority of what you will be doing is drilling into the hull and then placing screws into those holes. While there are things to watch out for and pitfalls to avoid with the installation of a new fish finder, you won’t need much to do the job correctly. 

Drilling Holes 🔩

Each unit will come with a template. While you definitely want to drill as few holes in the boat as possible during the installation, you most definitely want to only drill the holes that are necessary for the transom for the transducer. A miss drill hole here can create some genuine headaches later on. 

In the event, you miss-drill a hole, have some silicone on standby. Fill the hole and allow it to dry completely. Once the hole is filled, ideally after 24 hours, cover both sides of the hole with silicone to seal the plugin. Use clear or white marine-grade silicone for the best results in terms of aesthetics. 

A cautionary note on drilling, be very mindful of what is on the other side of the surface you are creating a hole in. Boats are limited in space, and a stray drill bit can easily damage fuel lines, steering cables, or other items that are extremely expensive to fix. Use a drill stop or a short drill bit to ensure that the only hole you drill is the one you want.

Setting Up the Wiring 🔌

Once you have mounted the transducer and have the head unit you want to install, the final component to install will be the wiring that connects everything. Generally speaking, the more sophisticated the unit you are installing, the more complex the wiring considerations.

As a general rule, keep any wires away from power lines to avoid electromagnetic interference. Don’t bunch up the cables or create very tight loops. Not only will this damage the wires, but it will create interference as well. 

Should a Fish Finder Be Wired Directly to a Battery? 🔋

There is a lively debate on if a fish finder should have its own dedicated battery. Both sides of the argument have valid points, and the truth is very vague. Ultimately, it depends on what unit you have and what you are doing in the boat.

If you can afford the space, weight, and expense of a battery that is dedicated to your fish finder, then do it. However, if you can’t, provided you don’t have a very high-end unit, you will be ok. You will just have to run the risk of other devices interfering with or even damaging your fish finder. 

Be Sure to Use Sealant Properly 💦

While there are many things that are different between kayak fishing and bass boat fishing, one thing that remains true, water must be kept out. Make sure that any application of a sealant is given plenty of time to dry and covers the area it is meant to seal completely.

Further, avoid getting sealant on the face of the transducer and other areas that could cause issues or interference with normal operation.

Wrapping Up 🏁

Installing a fish finder yourself is entirely possible, but you need to have some basic skills to do it. If you are not mechanically inclined and a complete novice to working on boats, then you may do well to take your boat to a shop and let them bring their expertise to bear on the project.

The more expensive and elaborate the unit, the more having a professional installation makes sense. You purchased a boat to allow you to access more spots than just fishing from the shore, but ensuring your fish finder is set up correctly will allow you to

Setting Up a Fish Finder: FAQs ❓

Are fish finders hard to install?

No, fish finders are not hard to install. Next to mounting fishing rod holders, fish finders are one of the easiest modifications you can do to your kayak that will yield the biggest results. Typically, it only requires four screws for the display, one or two screws for the transducer, and hooking up the battery. However, this all assumes that you have a basic familiarity with hand tools and are somewhat handy.

Does a fish finder need to be in the water to work?

A fish finder does not necessarily need to be in the water to work. While most transducers are meant to be mounted in the water on the transom of the boat, some transducers can be mounted in the hull. Aside from that, many fish finders have GPS and other functions integrated into them. These functions do not require the fish finder to be in the water to work.

How far away from the motor should a transducer be?

A transducer should be as far away from the motor as possible to allow for proper operation of the transducer without interference and in compliance with the guidelines of the manufacturer. Each transducer will come with installation guidelines and a template for the transom. Follow these instructions as closely as possible for the best results on the water. 

What angle should a transducer be set to?

You should set your transducer at an angle, so it is level when the boat is sitting in the water. This means that you should install your transducer at the angle required for it to sit level when the boat is in the configuration you will be using it in. This means with the most common level of fuel, equipment, people, and live well contents as you typically fish with. 

What can damage a transducer?

Anything in the water can damage a transducer. One of the chief malfunctions that befall fish finders is damaged transducers. In many cases, they simply get ripped off. However, scratches, dings, and cracks will also completely throw off the fish finder’s readings. This is precisely why knowing how to read a fish finder is important - you need to be able to identify potential equipment malfunctions.

What direction should a transducer face?

The transducer should face the direction that the installation guidelines call for. This is likely to have the cable running up the transom side to minimize drag and prevent it from snagging on things in the water.

How can I test a transducer out of water?

Yes, you can test a transducer out of the water. This can be accomplished by simply submerging the transducer in a container full of water. Often, the simplest way to do this is to place the transducer in a bucket of water. However, the hull transducers may present a challenge, though it can still be done in the same way.

Can a transducer shoot through the hull of a kayak?

Yes, you can shoot through the hull of a kayak. If you mount a transducer to the hull of your kayak, it will still work. This approach to mounting is much more difficult than simply wet sealing screws into the transom and should be done with care. Though this can’t go wrong in terms of damage to the hull, it can come to loss or give you false readings if you don’t do it correctly.