Chapter 4: Fishfinder Operations
4-3
Bot
tom Ind
ic
ati
ons
Effect of Frequency and Boat Speed
The return from a fish has a different appearance depending on the frequency
used: 50kHz produces a wide beam, so a fish spotted by this frequency gives a
broad arch; the 200 kHz beam is narrower so the same fish produces a
narrower arch.
The shape of the arch is also affected by the speed of the boat. If the boat is
moving slowly, the arches tend to be longer; if the boat is moving more
quickly, the arches are short and peaked. If the boat is moving very fast, a fish
may be indicated by a single vertical line.
In Bottom lock mode the fish arches may appear distorted as the bottom
topography is removed from the image.
Bottom Indications
The bottom usually produces a strong echo, so it is easy for the Fishfinder to
see a lot of detail. The Fishfinder can indicate many different kinds of bottom
conditions.
As illustrated in
Figure 4-2
, a hard bottom appears as a thin line.
Figure 4-2:
Fishfinder Bottom Indications
D5016-2
A
Hard bottom (sand)
B
Soft bottom (mud)
C
Rocky bottom
D
White line feature on:
Summary of Contents for hsb2 PLUS
Page 1: ...hsb2 PLUS Series Fishfinders Owner s Handbook Document number 81195_2 Date August 2002...
Page 2: ......
Page 34: ...1 22 hsb2 Plus Series Fishfinders Database Lists...
Page 64: ...2 30 hsb2 Plus Series Fishfinders Transmitted Data...
Page 110: ...4 14 hsb2 Plus Series Fishfinders MOB...
Page 160: ...5 50 hsb2 Plus Series Fishfinders Review Your Passage Plan...
Page 172: ...6 12 hsb2 Plus Series Fishfinders Data Log Mode...
Page 200: ...8 8 hsb2 Plus Series Fishfinders Worldwide Support...
Page 204: ...A 4 hsb2 Plus Series Fishfinders Appendix A Specifications...
Page 216: ...C 6 hsb2 Plus Series Fishfinders Appendix C C MAP Chart Card Features...
Page 228: ...viii hsb2 Plus Series Fishfinders...
