Specifications

Chapter 8-4 EQ33 Principles of operation
8.4 Effects of the vessel’s speed
The presentation of fish on the EQ33 depends directly on the vessel’s speed,
as well as on the depth of the fish. When the vessel is at rest, the echo traces
will appear stretched and flattened. As the vessel’s speed becomes greater, the
echo traces will become shorter and more arched. The reason for this change
in appearance is that as the vessel speed increases, fewer number of sound
‘pings’ strike each fish. A low vessel speed will provide the most accurate
information of where fish are located.