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Daniel Colloden used a under water bell to calculate the speed of sound underwater.
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Lewis Nixon invented the very first Sonar type listening device in 1906 as a way of detecting icebergs. Interest in Sonar increased during World War I when there was a need to be able to detect submarines.
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He made the first experimental unit, which was able to detect ice-bergs from a 2-mile range but couldn't determine a direction.
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In 1915, Paul Langévin invented the first sonar type device for detecting submarines called an "echo location to detect submarines" by using the piezoelectric properties of the quartz.
