Garmin 120 Dépliant

Sounds an alarm when the battery is reaching a critical state of discharge.

‘Shallow’ and ‘Deep’ can be set to sound a shallow/deep water warning at a depth 

determined by you. (If the either alarm is set and ‘Depth’ units are changed, both alarms 
default to ‘Off’.) These alarms may be set to ‘Off’ 

(default)

 or from 1-600 ft.

Sounds an alarm when the unit detects what it determines to be a fi sh. The alarm 

selections are: ‘Off’ 

(default)

 or ‘On’.

Determines how the graph displays underwater targets and background informa-

tion. If ‘Fish ID’ is set to ‘Off’, the unit displays all of the available information about 
the underwater environment. If a fish symbol is selected, the graph displays only the 
information related to that symbol (large, medium and small sizes).

     —  All available information is displayed. 

(default)

     —  Suspended targets displayed as symbols. No background information is 

 

 

displayed in this mode.

     —  Same as above with target depth displayed.
     —  Suspended targets display as symbols. In this mode background 

 

information is still displayed making fi sh identifi cation easier.

     —  Same as above with target depth displayed. 

This Garmin product is warranted to be free from defects in materials or workmanship for one year from 
the date of purchase. Within this period, Garmin will at its sole option, repair or replace any components 
that fail in normal use. Such repairs or replacement will be made at no charge to the customer for parts or 
labor, provided that the customer shall be responsible for any transportation cost. This warranty does not 
cover failures due to abuse, misuse, accident or unauthorized alteration or repairs.
THE WARRANTIES AND REMEDIES CONTAINED HEREIN ARE EXCLUSIVE AND IN LIEU OF ALL 
OTHER WARRANTIES EXPRESS OR IMPLIED OR STATUTORY, INCLUDING ANY LIABILITY ARISING 
UNDER ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, 
STATUTORY OR OTHERWISE. THIS WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS, WHICH 
MAY VARY FROM STATE TO STATE. 
IN NO EVENT SHALL GARMIN BE LIABLE FOR ANY INCIDENTAL, SPECIAL, INDIRECT OR CON-
SEQUENTIAL DAMAGES, WHETHER RESULTING FROM THE USE, MISUSE, OR INABILITY TO USE 
THIS PRODUCT OR FROM DEFECTS IN THE PRODUCT. Some states do not allow the exclusion of 
incidental or consequential damages, so the above limitations may not apply to you.
Garmin retains the exclusive right to repair or replace the unit or software or offer a full refund of the 
purchase price at its sole discretion. SUCH REMEDY SHALL BE YOUR SOLE AND EXCLUSIVE REMEDY 
FOR ANY BREACH OF WARRANTY. Products sold through online auctions are not eligible for rebates or 
other special offers from Garmin. Online auction confirmations are not accepted for warranty verification. 
To obtain warranty service, an original or copy of the sales receipt from the original retailer is required. 
Garmin will not replace missing components from any package purchased through an online auction.
To obtain warranty service, contact your local Garmin authorized dealer. Or call Garmin Customer 
Service for shipping instructions and a RMA tracking number. The unit should be securely packed with 
the tracking number clearly written on the outside of the package. The unit should then be sent, freight 
charges prepaid, to any Garmin warranty service station. A copy of the original sales receipt is required as 
the proof of purchase for warranty repairs.
The Fishfi nder 120 has no user-serviceable parts and is fastened shut with screws. Any attempt to open 
the case to change or modify the unit in any way will void your warranty and may result in permanent 
damage to the equipment.

By using the Fishfi nder 120, you agree to be bound by the terms and conditions of the following soft-
ware license agreement. Please read this agreement carefully.

Garmin grants you a limited license to use the software embedded in this device (the “Software”) in 
binary executable form in the normal operation of the product. Title, ownership rights and intellectual 
property rights in and to the Software remain in Garmin.

You acknowledge that the Software is the property of Garmin and is protected under the United States of 
America copyright laws and international copyright treaties. You further acknowledge that the structure, 
organization and code of the Software are valuable trade secrets of Garmin and that the Software in 
source code form remains a valuable trade secret of Garmin. You agree not to decompile, disassemble, 
modify, reverse assemble, reverse engineer or reduce to human readable form the Software or any part 
thereof or create any derivative works based on the Software. You agree not to export or re-export the 
Software to any country in violation of the export control laws of the United States of America

.

© Copyright 2003 Garmin LTD. or its subsidiaries
GARMIN

®

, DCG

®

 and See-Thru

®

 are registered trademarks of Garmin Ltd. or its subsidiaries 

and may not be used without the express permission of GARMIN.
Garmin International, Inc. 1200 East 151st Street, Olathe, Kansas 66062, U.S.A.
Tel.913/397.8200 Fax. 913/397.8282
Garmin (Europe) Ltd. Unit 5, The Quadrangle, Abbey Park Industrial Estate, Romsey, SO51 
9DL, U.K. Tel. 44/1794.519944 Fax.44/1794.519222
Garmin Corporation No. 68, Jangshu 2nd Road, Shijr, Taipei County, Taiwan
Tel. 886/2.2642.9199 Fax. 886/2.2642.9099

www.garmin.com  

 

 

Part Number 190-00306-00 Rev. A

Thank you for choosing the Garmin Fishfi nder 120. This product is designed for 

easy operation and to provide years of reliable service. Please read through these instruc-
tions to get the most out of your new unit. If you encounter a problem please contact 
our Product Support Department at 913-397-8200, Monday - Friday 8:00 a.m. to 5:00 
p.m. CST or on the internet at www.garmin.com/support.
Specifi cations
Case: Fully Gasketed, high-impact plastic alloy
Display:  3.1”H x 3.2”W (7.9 x 8.1 cm),  240 x 128 pixels
Size:  6.1” W x 4.9” H x 2.6 D (15.5 x 12.5 x 6.6 cm); Weight: 18.7 oz.
Temperature Range: +5° to 158°F (-15C to 70C)
Waterproof: IEC 529, level IPX-7 (submerged to 1 meter for 30 minutes)
Internal memory backup to retain user settings
Input: 10 to 18 Vdc w/ high voltage protection
Usage: 8 watts maximum, Nominal: 12 Vdc @ 0.5 amps
Sonar Power Output: 100 watts (RMS), 800 watts (peak to peak)
Frequency: 200kHz
Depth: 600 foot max depth 

(Depth capacity is dependent on water salinity, bottom type and other 

water conditions.) 
Specifi cations subject to change without notice.

The Fishfinder 120 is able to display a variety of useful information about the 
underwater environment. Below are a few things the unit helps you see.
Water Depth
The unit displays water depth and can provide a warning 
when a specific depth is encountered. The Depth 
Scale is displayed from top to bottom along the 
right side of the display. Messages and Alarm 
Icons are displayed along the bottom. 
Water Temperature
The unit displays the water temperature at the 
transducer.
Fish
The unit displays fish as arches or fish symbols in 
3 sizes and can alert you when a fish is detected.
Thermocline and Structure
GARMIN’s See-Thru

®

 technology can display 

more than just the thermocline and structure, the 
unit displays fish in and below the thermocline, 
trees, brush, and deadfall.
Bottom Shape and Type
Garmin’s unique DCG

®

 (Depth Control Gain) system provides

 a clear graphic representation of the bottom type and its shape.

ARROW KEYS
The UP and DOWN ARROW keys are used to 
select items on the Adjustment Menu and Setup 
menu. The LEFT and RIGHT ARROW keys are 
used to quickly cycle through Adjustment Menu 
settings.

ENTER Key
The ENTER key is used to activate/deactivate 
the Adjustment Menu and Setup Menu data 
fields for review or changes.

MENU Key
The MENU key is used to activate/deactivate 
Adjustment and Setup Menus.

POWER Key
The POWER Key is used to turn the unit on/off 
and to activate the display backlight. Press and 
hold to turn the unit on/off. Press briefly and 
release to activate the backlight. To change the 
backlight level, press the POWER key repeat-
edly to cycle between Off, Low and High.

Sets the display depth range. The unit can be set to automatically track the 

bottom or set to a user-specified range. Available settings are: ‘Auto’ (default) and 
15-600 ft.

Controls the sensitivity of the unit’s sonar receiver. This provides some flexibility 

in what is seen on the display. To see more detail, increase the receiver sensitivity by 
selecting a higher gain (+). If there is too much detail or if the screen is cluttered, 
lowering the sensitivity (-) may increase the clarity of the display. Available settings 
are: ‘Normal’ ( default) and +5 to -5.

Adjusts the rate that the graph scrolls from right to left. If you are sitting still or the 

graph is moving too fast, slowing or pausing the graph can be benefi cial.

Selects a display zoom scale. 

Available settings are: ‘OFF’ (default), ‘2X’ and ‘4X’ 

zoom.

‘View’ is available only when a Zoom scale other than ‘OFF’ is selected. This set-

ting allows you to select a specific zoom area to view on the display or allow the unit 
to automatically select a zoomed viewing area based on the bottom. When adjusting 
this setting, the top and bottom numbers reflect the zoomed view depth range.

The Adjustment Menu allows direct access to the 

settings most commonly changed while using the unit. 
These include the depth Range, Gain, Zoom, and the 
View settings. Current Adjustment Menu settings may 
be viewed by pressing the MENU key. Press MENU
again to hide the window or to exit any window. The 
current adjustment option always displays in the 
upper left of the display. Press LEFT or RIGHT on the 
ARROW keys to scroll through the available options.

To immediately change the current adjustment option, press the UP or DOWN

ARROW key. If you wish to review the available settings before making a change, 
press the ENTER key to activate the adjustment window.

1. Press MENU, then using the UP or DOWN ARROW key, move the selection arrow 

to the desired option and press ENTER. Choose ‘Setup’ for the main Setup Menu.

2. Using the UP or DOWN ARROW key move the selection arrow to the desired 

setting and press ENTER. (The selection arrow wraps when you reach the end of 
a menu and adjustment window. If holding the ARROW key down, release then 
press.) Holding down on an ARROW key rapidly advances the selection speed.

3.  To close a setting or menu window, press MENU.

Controls how the unit displays information about the bottom type (hard or 

soft). With Whiteline ‘Off’, the bottom return displays as solid black and contains no 
information on bottom hardness. With Whiteline ‘On’, the bottom return becomes 
a grayscale pattern and can be used to determine bottom hardness. 

A hard bottom 

returns a stronger signal and displays a thicker bottom layer. A weaker (soft) bottom 
return displays a thinner bottom layer. The selections are: ‘Off’ or ‘On’ 

(default)

.

Filters unwanted noise from the graph (especially when moving at faster speeds) 

and can be turned ‘Off’ or set to a fi xed value from 1-100%. Remember when setting the 
‘Noise Reject’, the higher the noise rejection setting, the more likely the unit does not 
show fi sh or structure. The selections are: 1-100% 

(default 50%) or 

‘Off’.

Displays either ‘Normal’ (default) or ‘Large’ depth, temp. and battery numbers.

Choose to either ‘Hide’ (default) or ‘Show’ the current battery voltage.

‘Water Temp’ automatically displays when set to ‘Auto’ (default) or you may choose 

to ‘Hide’ the temperature numbers. Water temperature will only display if you have a
temperature capable transducer.

Choose to display measurements in Feet (ft, default), Meters (m) or Fathoms (fa). (If 

the ‘Depth Alarm’ is set when ‘Units’ are changed, the ‘Depth Alarm’ is defaulted to ‘Off’) 

Choose to display the water temperature in Fahrenheit (°F, default) or Celsius (°C)

The Fishfinder 120 comes with a built-in simulator mode that allows you to 

practice and learn the operation of the unit at home rather than on the water. The 
unit indicates that it is running the simulator mode by displaying a message in the 
lower left of the display. While in the simulator mode, the unit displays a random 
bottom scene and the Fishfinder 120 can be controlled (except Noise Reject and 
Gain) just as if it were on the water. To exit the Simulator, turn the unit off. If no 
keys are pressed for 2 minutes, the unit automatically resets to default unit settings 
while in simulator mode. If the unit does not detect a transducer attached, it auto-
matically starts in Simulator mode.

Adjusts to compensate for different light levels or viewing angles.  

This option allows you to restore the factory default settings for the unit.

To understand what the unit is displaying, it is important to have a general knowl-

edge of how the unit works and how it determines what to display. The unit operates by 
transmitting sound waves toward the bottom of a lake, stream, or seabed in a cone shaped 
pattern. The area covered by the transmitted sound waves is determined by the cone 
angle of the transducer and the water depth. Using 
Garmin’s standard 20° transducer, the coverage is 
approximately 1/3rd of the water depth. The coverage 
area at a 30-foot depth is approximately a 10-foot 
diameter circle. 

When a transmitted soundwave strikes an 

underwater object, sound is reflected back to the 
transducer. The transducer collects the reflected sound 
waves and sends the data to the unit to be processed 
and displayed on the graph. The underwater data is 
displayed on the graph in the order that it is returned: 
first returned—first on the graph. Generally speaking, 
if the only thing between the transducer and the 
bottom is water, the first strong return comes from 
the bottom directly below the transducer. The first 
strong return sets the bottom level. Weaker secondary 
returns provide the detailed data. A fi sh may be in the 
coverage area of the transducer, but remember the fi rst 
strong return sets the bottom level. Any fi sh in a Dead 

Zone is not detected by the sonar. The 
fi sh is never detected since the bottom 
level is never set below the fi sh. The 
fi sh on the right side of the display 
(shown in light grey) is detected and 
displayed when the transducer cone 
passes over the fi sh.

It is important to understand that 

the unit does not display a 3-D repre-
sentation of the underwater environ-
ment. The unit can display multiple 
things (such as a fi sh and a tree) at 
the same time but can not determine 
where the return originated, only when 
it was received. Remember that the 
Fishfi nder displays a 2-D picture of the 
underwater environment. A fi sh and an 
underwater structure could be located 
anywhere in the coverage area at that 
slice of time.

1'

10'

9'

8'

7'

6'

5'

4'

3'

2'

3'

6'

9'

12'

15'

18'

21'

24'

27'

30'

(Simulated display)

Warning: This product, its packaging, and its components contain chemicals known to the State 
of California to cause cancer, birth defects, or reproductive harm. This Notice is being provided 
in accordance with California’s Proposition 65. If you have any questions or would like additional 
information, please refer to our web site at www.garmin.com/prop65.

Dead Zone