Simrad EQ60 - Manual (Page 97)

Instruction manual
85
857-164342 / Rev.C
Environment
The Environment dialogue box is available from the Install
menu.
Many other echo sounders are calibrated to a sound velocity of
1500 m/s. If the EQ60 is used together with other sounders it is
advantageous to adjust the sound velocity on the EQ60 as well,
in order to have the same depth readings.
Salt Water / Fresh Water - Propagation losses due to
absorption are much higher in sea water than in fresh water.
Correct compensation for these losses therefore relies on the
echo sounder knowing which water type is present.
Sound Velocity - For accurate measurement of bottom depth the
correct sound velocity must be entered. Normally, 1470 m/s is a
good average value.