Navman FISH 4500/4600 User Manual

The FISH 4500/4600 has two parts:

- the transducer attached to the hull
- the display unit.

The transducer generates an ultrasonic pulse 
(sound that is above the hearing range of the 
human ear), which travels down towards the 
bottom at a speed of about 4800 ft/sec (1463 m/
sec), spreading out into a cone shape.
When the pulse meets an object, such as a 
fish or the bottom, it is partly reflected back 
up towards the boat as an echo. The depth 
of the object or bottom is calculated by the 
FISH 4500/4600 by measuring the time taken 
between sending a pulse and receiving the 
echo. When an echo has been returned, the 
next pulse is sent.

The FISH 4500/4600 converts each echo into 
an electronic signal, displayed as a vertical line 
of pixels. The most recent echo appears on the 
extreme right of the display, with the older echoes 
being scrolled towards the left, eventually disap-
pearing off the display. 

The scroll speed depends upon the water depth 
and scroll speed setting. See section 3-2 Setup 
> Sonar and section 4-1 Interpreting the display, 
for more information. 

The appearance of echoes displayed are af-
fected by: 

• 

the fishfinder settings (frequency selected, 
range and gain settings)

• 

echoes (different fish types, different bot-
tom types, wrecks and seaweed)

• 

noise (water clarity and bubbles). 

See section 4-1 Interpreting the display, for more 
information.

FISH 4500/4600 Installation and Operation Manual

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