Raymarine gS Series, Installation And Operation Instructions Manual, Page: 97 / 208

Sonar is effective at a range of speeds. In deeper waters the
CHIRP bandwidth is automatically optimized to improve bottom
lock and the detection of moving objects (e.g. fish) in the wider
water column.
CHIRP sonar screen example
CHIRP DownVision TM overview
DownVision TM produces a wide–angle side-to-side beam and a
thin fore-to-aft beam. The coverage of the DownVision TM beam
is a water column directly beneath and to the sides of the vessel.
DownVision TM beam
D12777-2
DownVision TM is effective at lower vessel speeds. In deeper
waters the CHIRP bandwidth is automatically optimized to
improve bottom lock and the detection of moving objects (e.g.
fish) in the wider water column.
The wide, thin beam produces clear target returns. The use of
CHIRP processing and a higher operating frequency provide
a more detailed image, making it easier to identify bottom
structures around which fish may reside.
CHIRP DownVision TM screen example
17.3 Raymarine sonar modules
You can find details on Raymarine’s sonar modules below.
The depth shown below for DownVision TM sonar modules
is typical achievable depth, depending on the connected
transducer in optimum water conditions. The depths shown for
Traditional and CHIRP sonar modules are the maximum depths
achievable depending on connected transducer in optimum
water conditions.
2 500 m ( 8, 2 02 f t. )
3000 m (9,843 ft.)
2 000 m ( 6, 5 62 f t. )
1500 m (4,921 ft.)
1000 m (3,281 ft.)
8 00 m ( 2, 6 25 f t. )
5 00 m ( 1, 6 40 f t. )
190 m (623 ft.)
9 0 m ( 295 f t. ) 9 0 m (295 ft.) ) f t t ) t . ) 9 0 m (295 ft. ) 90 m (295 ft.) 9 0 m ( 295 f t. )
T raditional (600 W)
D ownVision
T raditional (1 kW)
C HIRP (1 kW)
Sonar module Technology / Description
CP450C CHIRP external
CP100
DownVision TM external
Dragonfly DownVision TM internal
a68 / a78 DownVision TM internal
CP300 Traditional external
a67 / a77 Traditional internal
c97 / c127 Traditional internal
e7D / e97 / e127 Traditional internal
DSM25 / DSM30 / DSM300 Legacy external
Fishfinder application
183