References
http://www.dosits.org/science/soundmovement/speedofsound/
http://www.nauticalcharts.noaa.gov/csdl/svp.html
http://www.oceanscience.com/news/detail.aspx?nid=80
http://resource.npl.co.uk/acoustics/techguides/soundseawater/
file://localhost/Users/Signe/Desktop/Signe_Johnson/twocolumn1.html
Mackenzie, Kenneth V. (1981). "Discussion of sea-water sound-speed determinations". Journal of the Acoustical Society of America 70 (3): 801–806. Bibcode:1981ASAJ...70..801M. doi:10.1121/1.386919.
http://www.sailblogs.com/member/chmaster/?xjMsgID=123634
http://www.tpub.com/weather3/2-6.htm
http://en.wikipedia.org/wiki/Sound_velocity_probe
http://en.wikipedia.org/wiki/Underwater_acoustics
http://en.wikipedia.org/wiki/Speed_of_sound