Glossary
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Glossary of Terms
Aft:
Near or toward the rear part of the boat (nautical
term).
Background noise: False or meaningless echo returns produced by
bubbles, water turbulence, or debris
Bow:
The front of the boat (nautical term).
Cavitation:
Air bubbles in the water which affect the readings
of a transducer. These are normally caused by
mounting the transducer at an incorrect angle or
location.
Chart Speed:
The rate at which echoes scroll across the display.
Cursor:
On a setup display, the place where the unit is
ready to make a change or enter new information.
This point is highlighted. You can move up or
down the list or display using the up- and down-
controls on the Trackpad.
Deadrise angle:
The slope or angle of the underside of the hull,
measured in the side-to-side direction.
Default value:
A value or setting which is pre-loaded into the unit
at the factory.
Fairing block:
A block used when mounting a thru-hull
transducer. The fairing block shims the
transducer to align it on a perfect horizontal plane
versus the rise of the hull.
Fathom:
A unit of depth equal to 6 feet.
Frequency:
The rate at which a sound source vibrates, or the
rate at which a sound wave changes.
Fore:
Near or toward the front part of the boat (nautical
term).
Gain:
The ability of a receiver to distinguish between
echoes of different strengths. In general, use a
higher gain setting for deep water, and a lower
setting for shallow water.
Keel:
The center of the hull, running from the bow to the
stern.
