From Wikipedia, the free encyclopedia
A
fishfinder is a type of
fathometer, both being specialized types of
echo sounding systems, a type of Active
SONAR.
('Sounding' is the measurement of water depth, a historical nautical
term of very long usage.) The fishfinder uses active sonar to detect
fish and 'the bottom' and displays them on a graphical display device,
generally a
LCD or
CRT screen. In contrast, the modern fathometer (from
fathom
plus meter, as in 'to measure') is designed specifically to show depth,
so may use only a digital display (useless for fish finding) instead of
a graphical display, and frequently will have some means of making a
permanent recording of
soundings
(which are merely shown and subsequently electronically discarded in
common sporting fishfinder technology) and are always principally
instruments of navigation and safety.
The distinction is in their main purpose and hence in the features
given the system. Both work the same way, and use similar frequencies,
and, display type permitting, both can show fish and the bottom. Thus
today, both have merged, especially with the advent of computer
interfaced multipurpose fishfinders combining
GPS technology, digital chart-plotting, perhaps
radar and electronic compass displays in the same affordable sporting unit.
