Fish Finder Reviews
Humminbird 325 FishFinder Review

Humminbird 325 FishFinder Review

This is one fantastic Product I found from Humminbird and I couldn’t believe the low cost. I was very excited about doing the review for this model from Humminbird.

It has all the features of the more expensive models out there but you don’t have to have a lot of space or a lot of money to experience a product with these great capabilities.It has powerful sonar technology built into a very small unit.

I was absolutely amazed at the simplicity and low cost of this unit. If you need to save space, but don’t want to compromise performance, look any further than the all-new Humminbird 325 Fish Finder.

I guarantee you will love all the features and simplicity of this unit.

Humminbird 325 Features

  • 4-Inch Diagonal Screen
  • 320V X 240H Pixel Screen
    • Pixels, The “picture elements“, or small square blocks, that make up the image on the LCD
    • Measured as a vertical by horizontal number (i.e. 640V x 320H), this key specification
      typically indicates the quality of resolution. In fish finders, the total resolution (vertical
      multiplied by horizontal) is often less important than the “Vertical Pixel“ resolution because
      a greater number of vertical pixels provide finer resolution of targets detected by sonar.
    • Sonar information on the horizontal axis can vary greatly, depending on boat speed and the Chart Speed setting.
  • 16 Level Grayscale (The use of varying shades of gray to represent the strength of the sonar signal on the display. Traditionally, the strongest sonar signals are represented in black, and
    progressively weaker signals are represented in progressively lighter shades of gray.)
  • IP67 Waterproof/Submersible @ 1 m for 30 minutes and dust tight.
    • The use of varying shades of gray to represent the strength of the sonar signal on the display. Traditionally, the strongest sonar signals are represented in black, and progressively weaker signals are represented in progressively lighter shades of gray.
  • 1000 ft. Depth Capability
  • Dual Beam Sonar

Humminbird 325 Sonar Options

  • Dual Beam Sonar
    • Your 300 Series™ Fishing System uses a 200/83 kHz Dual Beam PLUS™ sonar system with a wide (60°) area of coverage. DualBeam PLUS™
    • Sonar has a narrowly focused 20° center beam, surrounded by the second beam of 60°, expanding your coverage to an area equal to your depth.
    • In 20 feet of water, the wider beam covers an area 20 feet wide. DualBeam PLUS™ sonar returns can be blended together, viewed separately, or compared side-by-side. DualBeam PLUS™ is ideal for a wide range of conditions, from shallow to deep water in both fresh and salt water.
  • Switchfire Sonar
    • SwitchFire™ controls how the sonar returns are displayed in the Sonar Views.
    • SwitchFire™ settings are available on the Sonar Menu Tab.
    • To see the maximum sonar information available within the transducer beam so more fish arches and better jig tracking are shown, choose Max Mode.
    • To see a lot less clutter and more fish size accuracy interpreted from the transducer beam, choose Clear Mode.
  • Split Screen Zoom
  • Split Screen Bottom Lock
  • Wide Narrow Cone Split Screen
  • Instant Image Update
  • Selective Fish ID+
  • Real Time Sonar RTS Window
    • A Real Time Sonar (RTS™) Window appears on the right side of the display in the Sonar View only.
    • The RTS Window™ updates at the fastest rate possible for depth conditions and shows only the returns from the bottom, structure, and fish that are within the transducer beam.
    • The RTS Window™ plots the depth and intensity of a sonar return.
  • Sonar Echo Enhancement
  • TrueArch Technology
Humminbird 325 FishFinder
Humminbird 325 FishFinder

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How Sonar Works

Sonar technology is based on sound waves. The 300 Series™ Fish finder uses sonar to locate and define a structure, bottom contour, and composition, as well as depth directly below the transducer.

Your Humminbird 325 Fish Finder sends a sound wave signal and determines distance by measuring the time between the transmission of the sound wave, and when the sound wave is reflected off of an object; it then uses the reflected signal to interpret location, size, and composition of an object.

Sonar is very fast. A sound wave can travel from the surface to a depth of 240 ft (70 m) and back again in less than 1/4 of a second. It is unlikely that your boat can “outrun“ this sonar signal and if it can I might want it…


  • 300W rms
  • Transducer – Standard: XNT-9-20-

Depth Capabilities

Settings: AUTO, 10 to 1000 ft.

Max Depth controls the maximum depth of operation. When Max Depth is set to Auto, the Fish finder will locate bottom readings as needed (within the capacity of the unit).

When Max Depth is set to match your fishing maximum depth, your Fish finder will not attempt to acquire sonar data below that depth, so more detail will be shown on the screen.

NOTE: If the bottom is deeper than the Max Depth setting, the digital depth readout will flash, indicating that the Fish finder cannot locate the bottom.


  • 4.0″ diagonal
  • 320V x 240H
  • 16 Level Grayscale
  • Dual Beam Plus
  • Backlight


Simple as it gets:

  • Press the POWER/LIGHT key
  • When the Title screen is displayed, press the MENU key to access the Start-Up Options Menu.
  • Use the 4-WAY Cursor Control key to select Normal

Frequency, Watts, Power, and Cables

Energy Power, the amount of sound energy emitted into the water by the transducer’s transmitter.

Power output is measured using either RMS (Root Mean Square) or P-T-P (Peak-to-Peak) measurement systems. Either method is acceptable, but it is important when comparing power outputs, to make sure that the same measurement system is being used for both outputs because P-T-P numbers are 8 times higher than RMS numbers.

Greater power output allows the sonar signal to penetrate through weeds and thermoclines,(*Layer of water with temperature change) reach deeper depths and operate more efficiently in noisy environments, such as when the boat is running at high speed.

  • Root Mean Square (RMS) measures power output over the entire transmit cycle.
  • Peak to Peak measures power output at the highest points.

The benefits of increased power output are the ability to detect smaller targets at much greater distances.

  • 300 watts (RMS)
  • Power requirement, 10 -20 VDC
  • 2400 Watts (Peak to Peak)
  • Transducer Cable Length is a generous 20 ft.

Humminbird 325 FishFinder Pros & Cons

Humminbird 325 Pros

  • Finding fish is easy with fish ID and it beeps when it finds some so you don’t even have to watch it for it to alert you. Kind of nice, especially when you don’t have to constantly be watching the unit.
  • Quick view change is very helpful so you can see large views for people with bad eyes like myself.

Humminbird 325 Cons

  • As far as users of this unit is concerned I really couldn’t find much of anything being said that was negative.

I honestly feel this is a very nice unit with a lot of features found on only expensive models and would have no problem recommending this to a friend.

Alarms and Alerts

Depth, Fish ID Alarm, Low Battery, Temperature and Alarm Tone with this unit.

Mounting System

  • Mount: quick disconnect
  • Transducer mounting: inside hull or transom


Unit size: 5.25″W x 5.12″H x 1.12″D




Humminbird 325

In the Box

  • Humminbird 325
  • Transducer
  • Hardware
  • Mounting Bracket
  • Instructions