By Capt. Alan Mullis
begin to talk about Structure Scan without first touching on the
HDS units themselves. Lowrance HDS units are available in a 5”,
7”, 8”, and 10” screen size. The five and seven inch screens
only split in two panes while the eight and ten inch will give a
four panel view. The eight and ten inch screens also have
convenience buttons and a zoom wheel behind the cursor control.
However, the five inch unit will do anything the ten inch unit
will do; you just have to menu through until you find the
adjustment you are looking to change. One of the most prolific
complaints I hear is “I just bought my Lowrance unit four or
five years ago and now it’s out dated.” Well, I believe that
Navico has helped to solve that problem with the Plug & Play
head features of their Lowrance and Simrad units. With the help
of a NMEA 2000 starter kit and/or an Ethernet cable, options
like the LWX-1 Sirius Weather and radio antenna/receiver, BR24
Radar, EP Temperature sensor, EP Fuel Flow sensor, EP Fuel Level
sensor, Sonic Hub, other HDS units, LSS-1 Structure Scan, and
many other options can be plugged into these heads for years to
Scan Sonar, unlike competitors units, combines the Broadband
Sounder with Side Scan and Down Scan Imaging into one powerful
angling tool. When Broadband Sonar is overlaid on the Down Scan
Imaging it removes the guess-work and reveals fish and structure
more accurately than either do alone. The Track-back feature
allows the angler to scroll through sonar history and Chart
Plotter trail (from either sonar or Structure Scan) and display
and mark waypoints while continuing to record data and reviewing
history. Structure Scan can easily be networked with up to three
displays without the expansion port to allow viewing of
Structure Scan on all displays on the network.
The Side Scan full screen view will give detailed imaging with
480 feet side to side coverage underwater. The Down Scan allows
you to see images under the boat exactly as they appear. When
Structure Scan is used on a split screen with 2-D sonar a better
understanding of 2-D sonar can be obtained.
The LSS-1 consists of a box and a transducer with three crystals
inside projecting straight down and both left and right. The two
frequencies used are 455 and 800 which will not interfere with
83/200 transducer. The two transducers should be mounted within
18” of each other so the Broadband Sonar can overlay the Down
Scan Imaging for better fish detection.
When using the lower 455 kHz output,
the system provides clear sharp side scanned images on both left
and right out to 250 feet, as well as down scanned images to a
maximum depth of 300 feet. Switching to the higher 800 kHz
output further increases image definition while sacrificing some
distance in range.
When a Structure Scan window is active, you can press the menu
key which will bring up the Structure Scan menu. Here you can
select one of eight color palettes and then select display
options. Every time a new palette is selected the contrast and
sensitivity should be adjusted to display the best picture.
Remember that fish will appear as bright specks and not arches
when using Structure Scan due to the narrow cone.
Remember, when recording sonar, always save it to an MMC card or
the hard drive will fill up very quickly. The larger the side
scan distance the smaller the targets will be. The longer the
shadow the taller the object, the longer the fish shadow the
higher in the water column the fish is holding. A short shadow
indicates the fish is closer to the bottom. Sometimes the
surface clutter will look like a school of bait fish, but you
can usually tell the difference because the surface clutter will
extend downward from the top of the water column.
competitors, Lowrance Structure Scan gives us great images from
two through ten mph and good images from ten to thirty mph. This
makes it an ideal tool for eliminating water for the tournament
angler. Docks and structure can be scanned to show if fish are
present or not. Many of the anglers that I talk to that use
Structure Scan say they are still fishing the same structure but
with Lowrance’s state-of-the-art Structure Scan they now fish it
the right way because now they “Get the Whole Picture”.
several companies that offer good training videos for both HDS
Units and Structure Scan. My favorite is from Dr. Sonar but
Bennett Marine has some good information as well.