A fishfinder is an electronic device, consisting of a display and a transducer that uses sound waves (Sound Navigation And Ranging, or sonar) to “see” things in the water under your boat.

A sonar device sends pulses of sound waves down through the water. When these pulses hit objects like fish, vegetation or the bottom, they are reflected back to the surface. The sonar device measures how long it takes for the sound wave to travel down, hit an object and then bounce back up.

If you hang out around a marina, boat launch or other places where fishermen are with their boats you’ll notice that just about every boat is equipped with a fish finder. It is considered an essential piece of equipment, but for most people it is a waste of money because it doesn’t help them catch more fish.

Fish finders detect the presence of fish primarily by detecting the air in their swim bladders. The air conserved in the swim bladder changes the sound path and reflects energy back. The fish finder detects this reflected energy and converts it into fish images on the screen.

A portable fish finder is a small device that uses sonar technology to detect things beneath the surface. It is great at detecting all kinds of fish, both small and large ones. The best thing about these gadgets is that they don’t need to be mounted on a boat to work.

Can fish detect fish finders is a hot discussion. However, in reality, it’s nearly impossible for fish to detect fish finders. Such devices don’t produce enough noise or waves to make them detectable. Neither is the frequency the transducer transmits audible enough to scare or notify fish of danger.

Noise and other distractions may also have different effects on different fish species.ie territorial fish such as coral trout and cod might be less likely to be spooked away then pelagics such as mackeral and tuna. Well there ya go. If thats to be believed then sounders do NOT scare fish.

It’s indisputable that they can sense it. It’s also highly unnatural. Sometimes it will bother fish and sometimes not. More precisely, it will probably bother certain individual fish more than others.

Depth ranges of 10,000 feet are standard with these broadband devices, which include sounders from all of the major brands.

It is not recommended to run a FishFinder and transducer on a boat that is not in the water as you will not get any readings from the transducer. Without the water, the transducer could burn out and have issues if left running for an extended period of time out of the water.

Transducers are essential parts to every fish finder. They send out and receive sonar waves. These waves, once emitted into the water, bounce off of different objects.

Here’s the quick answer: No, you can’t use a fish finder out of water, because the transducer is unable to send or receive sonar signals in air.

You will not be able to test out the transducer’s ability to read depth when the boat is not in water. The temperature feature of the transducer will work, but it will only be reading the air temperature since it is not in the water.

Here are the most common types of incorrect display readings that are caused by transducer errors:

1. Display shows surface reading, but no bottom reading.
2. Display shows wrong depth reading.
3. Display shows erratic readings (especially when the boat speeds up)

Connectors are often not inserted properly or the connector is not tightened and this leads to corrosion. Perform a check of fuses and circuit breaker connections. Disconnect the plug to the depth transducer and verify that the sounder unit powers up. If it doesn’t, you need the manufacturer’s assistance.

If you’re experiencing these issues then here’s the steps to follow.

1. Verify the battery is good. A failing will cause these issues.
2. Clean battery terminals.
3. Make sure your fish finder is wired direct to battery.
4. Solder or solder shrink all connections.
5. Make sure you’re using the correct gauge and style of wire.

Sonar interference, as seen on a fishfinder, chartplotter, or a display capable of showing sonar images will appear as if the screen is a blank, black screen, flasher seems to stop working or distorts the image. EMI (Electromagnetic Interference) near a sonar device typically causes interference.

Adjust Sonar Sensitivity Manually

1. Bring your boat to a depth you commonly fish (preferably more than 20ft).
2. Turn off the auto-sensitivity (gain) feature and turn off the auto-range feature (you can turn that back on later).
3. Manually adjust the range to more than twice the depth.

The gain setting controls the sensitivity of the sonar receiver to compensate for water depth and water clarity. Increasing the gain shows more detail, and decreasing the gain reduces screen clutter.

CHIRP stands for “Compressed High Intensity Radar Pulse.” That’s a fancy way of saying it can show you fish that other forms of 2D sonar can’t. By covering a wide range of frequencies, CHIRP produces more accurate, more detailed returns of fish, structure and the bottom.