Highest Rated Fishfinders
1Humminbird Helix 5 CHIRP G2
2Lowrance HDS 7 Gen3
3Garmin Striker 7sv
4Garmin echoMAP CHIRP 73sv
5Raymarine Dragonfly 7 PRO

Furuno FCV620

The Furuno FCV620 dual frequency color fish finder is the smaller sibling of the brawny Furuno FCV582 sounder. Like its big brother it features a rotary knob for gain control.

In our opinion, using a rotary knob for making quick and easy fine adjustments to the gain is a necessity for maximizing the usefulness of your fish finder. Normally only much more expensive sounders have this feature.

furuno fcv620 fish finder sounder

Furuno FCV-620

The FCV620 display unit has a square panel front that measured 6.7 inches across the width or height with a depth just under 4 inches.

The Furuno FCV620 fish finder package includes the display unit, power cable, owner’s manual, single-page quick reference guide, a beefy rotating single stanchion mounting bracket, and hardware to flush mount the display if you so choose.

All essential electronics are internal to the display. The only remaining component needed get full use out of this bottom machine is a transducer.

Several transducer options are available ranging from transom-mount units with water temperature sensing to a bronze thru-hull unit with both water temperature and speed sensors.

For our on the water testing we mounted the display using the accompanying bracket and found that it held the display unit securely.

A pair of ports on the case back connects to a power and transducer cable using twist-lock connectors. A single ground wire connection is on the back too. This fish finder can interface with other NMEA 0183 devices.

Screen Size and Viewability

The Furuno FCV620 has a color LCD screen measuring nearly 4.5-inches high and just over 3-inches wide. On the diagonal we measured the portrait layout screen at 5.6 inches. Screen resolution is 320 pixels vertically and 234 pixels on the horizontal plane.

We reviewed the Furuno FCV620 display screen on a sunny day with the unit mounted under a T-Top.

The display screen was fairly bright, adequately sharp and showed good contrast when viewed from straight-on.

We noticed very little screen darkening after donning polarized sunglasses.

However the screen does darken when viewed from severe side angles and finally blanks completely going beyond about 50 degrees.

The screen does exhibit a small amount of reflectivity. We gave it a good rating for daytime viewability.

A quick press of the on/off pushbutton brings up the brightness and contrast menu onscreen. Each can be adjusted to one of 10 levels.


On The Water Performance

furuno fcv620 fish finder sounder

The left side of this screen view shows the low frequency display, the middle section is the high frequency output, and the far right side is the A-scope column.
You can see the wide beam of the 50 kHz pulse found all three of our targets and painted a very distinctive fish arch shape for each. Less accuracy at this frequency made the deepest target arch somewhat less defined and merged it with the bottom echo.
The 200 kHz display and its narrow beam width clearly shows better target definition. It missed the shallowest target though due to close proximity and narrow beam width even though we tried to drive the test boat right over the targets.
We achieved our best results by using manual range and gain. Both settings are shown in the header line as is the gain setting of 8.9. In either auto gain setting the unit did not pick up our test targets as well as it did in manual mode.

Nighttime viewing is enhanced by choosing the night color palette. It uses a black background, white numbers and letters, and a blue/green color for painting targets. All the pushbuttons and knobs on the display face are backlit and brighten as the screen dims. We found it easy to achieve a good balance in low light conditions. We’d rate the screen good for night viewing.

Controls and Operation

Pushbutton and rotary knob controls are on the right side of the front panel. The main menu is reached with a press of the Menu/Esc key, then a selection is made with the cursor pad arrows, and finally the selection is accepted and executed with a press of the Enter key.

Below these key is the Range button, a press here brings up the depth range menu box and allows the user to choose between automatic or manual. When you arrow over to manual eight user adjustable range selections appear and can be selected with the up/down arrows.

If the Furuno FCV620 is connected to a GPS unit the mark button will save a waypoint when it is pressed. We did not connect the unit to a GPS to test this feature.

Next down is the Function key, with it you have one-button access to one of eight user selectable functions.

The rotary gain control knob is next in line and allows the user to switch between two automatic gain settings, fishing or cruising, and manual gain with successive presses of the knob. Manual gain is adjusted by rotating the knob and displayed in the header line at the top of the screen.

The next knob down affords instant selection of seven different modes of operation. Here you can choose one of two navigation data displays, full-screen high frequency, full-screen low frequency, either of the preceding two with zoom, as well as a dual frequency mode. Whenever a new mode is selected on the Furuno FCV620 a mode menu pops up onscreen for several seconds indicating the new mode.

Furuno FCV620 Specifications

Power (Watts RMS)600
Frequency (kHz)50 / 200
Transducer Used for TestAirmar B44V
Auto Depth RangingYes
Manual Depth RangingYes – 8 steps
GainAuto(2) / Manual
Bottom LockYes
Warranty Period (Years)(2)Parts / (2)Labor

You get the fastest screen refresh rate in either full-screen mode, adding zoom or choosing dual frequency slows the screen speed noticeably.

Functions and Features

Some notable features on the Furuno FCV620 are A-scope, shift, user selectable zoom, adjustable picture advance speed, variable depth display number size, a variety of color palettes, and user selectable data boxes.

A-scope can be turned off, to normal, or to peak. Peak leaves a trail in the A-scope column for several seconds after the initial data was written to help the user track faint signals more easily.

Zoom mode selection is accessed through the sounder menu and can be set to bottom lock, bottom zoom, or maker zoom. Bottom lock range can be set to between 10 and 30 feet while bottom zoom can be set to anywhere between 7 and 2500 feet.

Picture advance can be set to one of eight speeds ranging from stopped to 4 times the ping rate. For our testing we used the 1/1 speed setting which writes one column of pixels for each ping of the sounder.

The display screen color palette can be set to white, blue, black, monochrome, or night. We used the default white for our daytime testing due to bright sunny test conditions.

Up to two data boxes can be displayed onscreen, data points are user selectable.

A header line displayed at the top of the screen indicates the gain mode, range mode, and operational mode selected. When in manual gain the actual gain setting is displayed too. If battery voltage is turned on is shown here too. The header line can turned off is desired.

A calibration page allows the user to fine tune several inputs and settings. You can set your vessel draft here, increase or decrease the baseline auto gain settings, and fine-tune the water temperature and boat speed displayed. All of these types of adjustments are valuable in fine-tuning the FCV620 to your boat and your preferences.

Check out the updated version of this fishfinder, the Furuno FCV627 here.

Final Thoughts

The Furuno FCV620 has functions and features normally only found on much bigger and more expensive fish finders. Combine this with its excellent performance and you’ve got a winner. Make sure when you order this unit you add a transducer appropriate for your boat and usage.