Humminbird 748 3D User manual

531879-1EN_A
748 3D Operations Manual

Thank You!
Thank you for choosing umminbird®, America’s #1 name in fishfinders.
umminbird® has built its reputation by designing and manufacturing
top-quality, thoroughly reliable marine equipment. Your umminbird® is
designed for trouble-free use in even the harshest marine environment. In
the unlikely event that your umminbird® does require repairs, we offer an
exclusive Service Policy - free of charge during the first year after purchase,
and available at a reasonable rate after the one-year period. For complete
details, see the separate warranty card included with your unit. We
encourage you to read this operations manual carefully in order to get the full
benefit from all the features and applications of your umminbird® product.
To contact our Customer Resource Center, call 1-800-633-1468 or visit our
Web site at humminbird.com.
WARNING! This device should not be used as a navigational aid to prevent collision,
grounding, boat damage, or personal injury. When the boat is moving, water depth may
change too quickly to allow time for you to react. Always operate the boat at very slow
speeds if you suspect shallow water or submerged objects.
WARNING! Disassembly and repair of this electronic unit should only be performed by
authorized service personnel. Any modification of the serial number or attempt to repair the
original equipment or accessories by unauthorized individuals will void the warranty.
WARNING! This product contains chemicals known to the State of California to cause
cancer and/or reproductive harm.
WARNING! Do not travel at high speed with the unit cover installed. Remove the unit cover
before traveling at speeds above 20 mph.
ENVIRONMENTAL COM LIANCE STATEMENT: It is the intention of Humminbird® to be
a responsible corporate citizen, operating in compliance with known and applicable
environmental regulations, and a good neighbor in the communities where we make or sell
our products.
WEEE DIRECTIVE: EU Directive 2002/96/EC “Waste of Electrical and Electronic Equipment
Directive (WEEE)” impacts most distributors, sellers, and manufacturers of consumer
electronics in the European Union. The WEEE Directive requires the producer of consumer
electronics to take responsibility for the management of waste from their products to
achieve environmentally responsible disposal during the product life cycle.
NOTE: Some features discussed in this manual require a separate purchase, and
some features are only available on international models. Every effort has been
made to clearly identify those features. Please read the manual carefully in order
to understand the full capabilities of your model.

WEEE compliance may not be required in your location for electrical & electronic equipment
(EEE), nor may it be required for EEE designed and intended as fixed or temporary
installation in transportation vehicles such as automobiles, aircraft, and boats. In some
European Union member states, these vehicles are considered outside of the scope of the
Directive, and EEE for those applications can be considered excluded from the WEEE
Directive requirement.
This symbol (WEEE wheelie bin) on product indicates the product must not be
disposed of with other household refuse. It must be disposed of and collected for
recycling and recovery of waste EEE. Humminbird® will mark all EEE products in
accordance with the WEEE Directive. It is our goal to comply in the collection,
treatment, recovery, and environmentally sound disposal of those products; however, these
requirements do vary within European Union member states. For more information about
where you should dispose of your waste equipment for recycling and recovery and/or your
European Union member state requirements, please contact your dealer or distributor from
which your product was purchased.
ROHS STATEMENT: Product designed and intended as a fixed installation or part of a
system in a vessel may be considered beyond the scope of Directive 2002/95/EC of the
European Parliament and of the Council of 27 January 2003 on the restriction of the use of
certain hazardous substances in electrical and electronic equipment.
700 Series™, Fish ID+™, umminbird®, RTS™, RTS Window™, Structure ID®, SwitchFire™,
WhiteLine™, and X-Press™ Menu are trademarked by or registered trademarks of umminbird®.
© 2010 umminbird®, Eufaula AL, USA. All rights reserved.
ATTENTION INTERNATIONAL CUSTOMERS: Produ ts sold in the U.S. are not
intended for use in the international market. Humminbird® international units provide
international features and are designed to meet ountry and regional regulations.
Languages, maps, time zones, units of measurement, and warranty are examples of
features that are ustomized for Humminbird® international units pur hased through
our authorized international distributors.
To obtain a list of authorized international distributors, please visit our Web site at
www.humminbird.com or onta t our Customer Resour e Center at [phone].

Power On the Unit 1
How Sonar Works 2
3D Sonar .................................................................................................................... 4
2D Sonar .................................................................................................................... 5
What’s on the 3D Sonar Display 6
What’s on the 2D Sonar Display 8
Understanding the 2D Sonar Display .................................................................... 10
Real Time Sonar (RTS™) Window .......................................................................... 10
SwitchFire™ ............................................................................................................ 11
Freeze Frame and Active Cursor.............................................................................. 11
Instant Image Update .............................................................................................. 11
Bottom Presentation ................................................................................................ 12
iews 14
3D Sonar View.......................................................................................................... 16
2D Sonar View.......................................................................................................... 18
2D/3D Sonar Combo View ...................................................................................... 19
6-Beam Sonar View ................................................................................................ 20
2D Zoom View.......................................................................................................... 21
2D Big Digits View .................................................................................................. 22
What’s on the 700 Series™ Control Head 23
Key Functions 24
POWER/LIG T Key .................................................................................................. 24
VIEW Key.................................................................................................................. 25
MENU Key................................................................................................................ 25
4-WAY Cursor Control Key ...................................................................................... 25
EXIT Key.................................................................................................................... 26
Accessory Bus 27
The Menu System 28
Table of Contents
i

Table of Contents
ii
Start-Up Options Menu 29
Normal.................................................................................................................... 29
Simulator ................................................................................................................ 30
System Status ........................................................................................................ 30
Self Test.................................................................................................................. 31
Accessory Test........................................................................................................ 31
PC Connect ............................................................................................................ 32
X-Press™ Menu 33
Main Menu 34
Quick Tips for the Main Menu .................................................................................. 35
Note for all Menu Settings.................................................................................... 35
User Mode (Normal or Advanced) ............................................................................ 36
Sonar X-Press™ Menu (Sonar Views only) 38
3D Bottom Zoom (3D Sonar, 3D/2D Sonar Combo Views only).................................... 39
3D Lower Range (3D Sonar, 3D/2D Sonar Combo, 6-Beam Sonar Views only) .............. 39
3D istory (3D Sonar, 3D/2D Sonar Combo Views only) .............................................. 39
2D Sonar Window (3D/2D Sonar Combo View only) .................................................. 40
Reset View (3D Sonar, 3D/2D Sonar Combo Views only).............................................. 40
6-Beam Sensitivity (6-Beam Sonar View only) .......................................................... 40
Sensitivity (2D Sonar, 2D Sonar Zoom, 2D Big Digits Views only).................................. 41
Upper Range (Advanced: 2D Sonar, 2D Big Digits Views only) .................................... 42
Lower Range (2D Sonar, 2D Sonar Zoom, 2D Big Digits Views only) ............................ 42
Chart Speed (2D Sonar, 2D Sonar Zoom, 2D Big Digits Views Only) .............................. 43
Bottom View (2D Sonar, 2D Sonar Zoom, 2D Big Digits Views Only) ............................ 43
Zoom Level (2D Zoom View only) .............................................................................. 43
Alarms Menu Tab 44
Depth Alarm............................................................................................................45
Fish ID Alarm ..........................................................................................................45
Low Battery Alarm..................................................................................................45
Temp. Alarm ............................................................................................................46
Alarm Tone ..............................................................................................................46

iii
Sonar Menu Tab 47
3D Bottom Style (3D Sonar Views only) ...................................................................... 48
3D Frame Style (3D Sonar Views only) ........................................................................ 48
2D Beam Select........................................................................................................ 48
Surface Clutter ........................................................................................................ 49
SwitchFire™ ............................................................................................................ 49
Fish ID+™ ................................................................................................................ 50
Fish ID Sensitivity .................................................................................................... 51
Fish ID 3D Reference (3D Sonar Views only) .............................................................. 52
Real Time Sonar (RTS™) Window (2D Sonar View only) .......................................... 52
Zoom Width (2D Zoom View only) .............................................................................. 52
83 k z Sensitivity (Advanced, 2D Sonar Views only) .................................................... 53
Depth Lines (Advanced, 2D Sonar Views only).............................................................. 53
Noise Filter (Advanced) .............................................................................................. 54
Max Depth (Advanced, 2D Sonar Views only) .............................................................. 54
Water Type (Advanced) .............................................................................................. 54
Setup Menu Tab 55
Units – Depth .......................................................................................................... 56
Units – Temp (International only) ................................................................................ 56
Units – Distance (with Temp/Speed or GPS Receiver) .................................................. 56
Units – Speed (with Temp/Speed or GPS Receiver) ...................................................... 56
User Mode................................................................................................................ 57
Language (International only)...................................................................................... 57
Triplog Reset (with Temp/Speed or GPS Receiver) ........................................................ 57
Restore Defaults ...................................................................................................... 57
Select Readouts (Advanced, 2D Sonar and 3D Sonar Views only).................................. 58
Depth Offset (Advanced)............................................................................................ 59
Digits Format (Advanced) .......................................................................................... 59
NMEA Output (Advanced).......................................................................................... 60
Speed Calibration (Advanced, with Temp/Speed only).................................................. 61
Demonstration.......................................................................................................... 61
Sound Control .......................................................................................................... 61
Table of Contents

iv
iews Menu Tab 62
Accessories Menu Tab 63
Troubleshooting 64
Fishing System Doesn’t Power Up........................................................................ 64
Fishing System System Defaults to Simulator with a Transducer Attached...... 64
Display Problems .................................................................................................. 65
Finding the Cause of Noise .................................................................................. 66
700 Series™ Fishing system Accessories 67
Specifications 68
Glossary 69
Contact Humminbird® 73
NOTE: Entries in this Table of Contents which list (International Only) are only
available on products sold outside of the U.S. by our authorized international
distributors. To obtain a list of authorized international distributors, please visit our
Web site at humminbird.com or contact our Customer Resource Center at (334)
687-6613.
NOTE: Entries in this Table of Contents which list (with Temp/Speed only) require
the purchase of separate accessories. You can visit our Web site at
humminbird.com to order these accessories online or contact our Customer
Resource Center at 1-800-633-1468.
NOTE: Some features discussed in this manual require a separate purchase, and
some features are only available on international models. Every effort has been
made to clearly identify those features. Please read the manual carefully in order
to understand the full capabilities of your model.
Table of Contents

1
Power On
Follow the instructions below to power on your umminbird® control head.
1. Press the POWER/LIG T key.
2. When the Title screen is displayed, press the MENU key to access the
Start-Up Options Menu.
3. Use the 4-WAY Cursor Control key to select Normal (if there is a
transducer attached to the control head) or Simulator (if there isn’t a
transducer attached to the control head).
NOTE: See Start-Up Options Menu for more information.
•If a functioning transducer is connected, Normal operation will be
selected automatically at power up, and your Fishing System can
be used on the water.
•If a transducer is not connected and you wait too long to select a
Start-Up Option, the system will default to whichever menu is
already highlighted.
• In Simulator you can learn how to use your control head and save
settings in advance for later use.
748 Title Screen
Power On

2
How Sonar Works
Sonar technology is based on sound waves. The 700 Series™ Fishing System
uses sonar to locate and define structure, bottom contour and composition, as
well as depth directly below the transducer.
Your 700 Series™ Fishing System 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.
SONAR is an acronym for SOund and
NAvigation Ranging. Sonar uses precision
sound pulses or “pings“ which are emitted
into the water in a teardrop-shaped beam.
The sound pulses “echo“ back from objects
in the water such as the bottom, fish, and
other submerged objects. The returned
echoes are displayed on the LCD screen.
Each time a new echo is received, the old
echoes are moved across the LCD, creating
a scrolling effect.
How Sonar Wor s

3
When all the echoes are viewed side by side, an
easy to interpret “graph“ of the bottom, fish, and
structure appears.
The sound pulses are transmitted at various
frequencies depending on the application. Very
high frequencies (455 k z) are used for greatest
definition but the operating depth is limited. igh
frequencies (200 k z) are commonly used on
consumer sonar and provide a good balance
between depth performance and resolution. Low
frequencies (83 k z) are typically used to achieve
greater depth capability.
The power output is the amount of energy
generated by the sonar transmitter. It is commonly
measured using two methods:
• Root Mean Square (RMS) measures power
output over the entire transmit cycle.
• Peak to Peak (PtP) measures power output at
the highest points.
The benefits of increased power output are the
ability to detect smaller targets at greater distances,
ability to overcome noise, better high speed
performance and enhanced depth capability.
How Sonar Wor s

4
3D Sonar
Your Fishing System uses a six-
element transducer that transmits at
455 k z and is capable of reaching
depths of 240 ft (75 m). Each
transmitted beam is symmetrical and
16 degrees in width. The six beams
are lined up next to each other to
provide a total coverage of 53 degrees
from side to side, and 16 degrees from
front to back.
Using multiple narrow beams together gives you a wide area of coverage for
terrain interpretation and fish location, without sacrificing the detail only a
narrow beam can provide. Your Fishing System gathers information from a
continuous series of these returned signals. It then interprets this information
to create a detailed 3-dimensional view of the terrain passing beneath your
boat as you travel across the water.
NOTE: Depth capability is affected by such factors as boat speed, wave action, bottom
hardness, water conditions, and transducer installation.
How Sonar Wor s

5
2D Sonar
Your Fishing System also has the
capability of displaying traditional
2-dimensional sonar information from
either a 455 k z beam or an 83 k z
beam.
The 455 k z single beam has the
advantage of providing increased
sonar resolution but is limited to a
depth capability of 240 ft (75 m). The
83 k z single beam sonar has the
advantage of providing sonar
information to 1000 ft (330 m) but
provides less resolution than the 455
k z beam.
NOTE: Depth capability is affected by such factors as boat speed, wave action, bottom
hardness, water conditions, and transducer installation.
How Sonar Wor s

What’s on the 3D Sonar Display
In 3D views, your Fishing System can display a variety of useful information
What’s on the 3D Sonar Display 6
NOTE: Entries in this view that list (with Temp/Speed or GPS Receiver) are available if
the information from the GPS receiver will be displayed on the view.
Speed - If a Temp/Speed a essory or
GPS Re eiver is atta hed, the Fishing
System an display the speed of the boat
and an keep a Triplog of nauti al or
statute miles traveled.
Bottom Contour - Shows the shape of the
bottom derived from depth measurements
on 6 beams. 3 bottom styles are available;
the front edges of the bottom ontour
are outlined to reate a visual an hor.
The width of the bottom overed is
approximately equal to the depth.
Temperature - Water surfa e temperature.
Depth - Water depth an be set to alarm
when the water be omes too shallow.
Timer - Elapsed time with Temp/Speed
A essory or GPS Re eiver.
Distance - Distan e traveled with
Temp/Speed A essory or GPS Re eiver.
Average Speed - Average speed
reading with Temp/Speed A essory or
GPS Re eiver.

about the area under and adjacent to your boat, including the following items:
What’s on the 3D Sonar Display
7
either device is connected to the Fishing System. If both devices are connected, then only
Fish D+™ - A fish i on will be shown at
the derived position of the fish. Six fish
i on styles will be used to indi ate the
primary beam in whi h the fish was
found. Left-fa ing fish indi ate fish off
the port side of the boat, while right-
fa ing fish indi ate fish off the starboard
side. Ea h fish i on is available in three
different sizes. Larger fish i ons are used
to represent stronger returns. The i ons
used in the 2D Sonar View are identi al
to the i ons used in the 3D Sonar View.
Boat/Direction Arrow - A simple, solid
3D boat is drawn when the Upper Depth
Range is 0. A solid 3D arrow is drawn
when the Upper Depth Range is not 0.
Upper and Lower Depth Range
Frame - Provides a referen e for bottom
and Fish ID information. A Range of
frame styles are available, from simple
to omplex.
Battery Voltage - The voltage of the
boat’s battery; an be set to alarm if the
voltage falls below a ertain point.

8
What’s on the 2D Sonar Display
What’s on the 2D Sonar Display
The 700 Series™ Fishing System can display a variety of useful information
NOTE: Entries in this view that list (with Temp/Speed or GPS Receiver) are available if
the information from the GPS receiver will be displayed on the view.
Depth - Water depth an be set to alarm when
the water be omes too shallow.
Temperature - Water surfa e temperature.
Timer - Elapsed time with Temp/Speed
A essory.
Distance - Distan e traveled with Temp/Speed
A essory.
Average Speed - Average speed reading with
Temp/Speed A essory.
Second Sonar Return - When the sonar signal
boun es between the bottom and the surfa e of the
water and ba k again. Use the appearan e of the
se ond return to determine bottom hardness. Hard
bottoms will show a strong se ond return, while soft
bottoms will show a very weak one or none at all.
Speed - If a Temp/Speed a essory is atta hed,
the Fishing System an display the speed of the
boat and an keep a Triplog of nauti al or statute
miles traveled.
Cursor Dialog Box - Displays on the view
when the ursor is a tive.

9What’s on the 2D Sonar Display
Structure - Where fish may be hiding.
Thermoclines - Layers of water with different
temperatures that appear at different depths
and different times of the year. A thermo line
typi ally appears as a ontinuous band of gray
levels moving a ross the display at the same
depth.
Bait Ball
Fish - The Fishing System displays fish as
ar hes and/or fish i ons, and an be set to
alarm when a fish of a ertain size is
dete ted. When a target is dete ted, a Fish
ID+™ symbol appears on the display with
the depth displayed above it. The size of the
symbol indi ates the intensity of the sonar
return. The unit will learly show s hools of
Bait Fish as ” louds” of different shapes and
sizes, depending on the number of fish and
boat speed.
Battery Voltage - The voltage of the boat’s
battery. It an be set to alarm if the voltage
falls below a ertain point.
Hollow Fish Symbol (see Fish ID+™)
Active Cursor
RTS (Real Time Sonar) Window™
about the area under your boat, including the following items:
either device is connected to the Fishing System. If both devices are connected, then only

10
Understanding the
2D Sonar Display
It is important to understand the significance of
the display. The display does not show a literal
3-dimensional representation of what is under the
water. Each vertical band of data received by the
control head and plotted on the display represents
something that was detected by a sonar return at
a particular time. As both the boat and the targets
(fish) may be moving, the returns are only showing
a particular segment of time when objects were
detected, not exactly where those objects are in
relation to other objects shown on the display.
The returned sonar echoes are displayed on the screen. As a new echo is
received, the historical data scrolls left across the view.
Real Time Sonar (RTS™) Window
AReal 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 (see Sonar Menu Tab: RTS Window™).
The Narrow RTS Window™
indicates the sonar intensity
through the use of grayscale.
The grayscale used matches
the Bottom View grayscale
setting (Inverse, StructureID
® ,
WhiteLine™, Bottom Black) .
The depth of the sonar return
is indicated by the vertical
placement of the return on the
display depth scale.
The Wide RTS Window™
indicates the sonar intensity
through the use of a bar
graph. The length of the
plotted return indicates
whether the return is weak or
strong. The depth of the sonar
return is indicated by the
vertical placement of the
return on the display depth
scale. The Wide RTS
Window™does not use
grayscale.
What’s on the 2D Sonar Display

11
SwitchFire™
SwitchFire™ controls how the sonar returns are displayed in the Sonar Views.
SwitchFire™settings are available in 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 less clutter and more fish size accuracy interpreted from the transducer
beam, choose Clear Mode. See Sonar Menu Tab: SwitchFire™for more
information.
Freeze Frame and Active Cursor
Press any arrow on the 4-WAY Cursor Control key, and the screen will freeze
and a cursor will be displayed. Use the 4-WAY Cursor Control key to move the
cursor over a sonar return, and the depth of the sonar return will be displayed
in the cursor dialog box.
NOTE: In 2D Sonar Views, the RTS Window™ continues to update in Freeze Frame.
To return to a scrolling display and exit Freeze Frame, press the EXIT key. Freeze
Frame is available in the Sonar and Sonar Zoom Views.
Instant Image Update
nstant mage Update - You can change a variety of sonar menu settings (such
as Sensitivity or Upper Range), and the adjustments will be shown instantly on
the screen.
What’s on the 2D Sonar Display

12
Bottom Presentation
As the boat moves, the unit charts the changes in depth on the display to create
a profile of the Bottom Contour. The type of bottom can be determined from
the return charted on the display. A Hard Bottom such as compacted sediment
or flat rock appears as a thinner line across the display. A Soft Bottom such as
mud or sand appears as a thicker line across the display. Rocky Bottoms have
a broken, random appearance.
The sonar returns from the bottom, structure, and fish can be represented as
nverse, Structure D®, WhiteLine™, or Black (Bottom Black). See
Sonar X- ress™Menu: Bottom View to set the Bottom View.
Bottom Contour Profile with RTS Window™
Hard Bottom
Rocky Bottom
Soft Bottom
What’s on the 2D Sonar Display