Figure 137: Concept of refraction due to different sound velocities in the water column
The velocity of sound in water varies both horizontally and vertically. It cannot be assumed that the
velocity of sound in the water column remains constant over large areas or throughout the day in a
more local area. The main influences on sound velocity are: Conductivity (salinity), Temperature and
Depth (pressure).
1 ° C change in Temperature
4.0 m/sec change in velocity
1.4 m/sec change in velocity
100 m change in Depth (10 atm’s pressure)
1.7 m/sec change in velocity
Figure 138: Sound velocity profile
Page 142 of 210
Version 5.0 Rev r002
Date 05-08-2014
Part No. 96000001