For instance, the idea that the Navy's sonar systems are harming whales is about as well based in fact as the 1960s fear that fluoride in our water was poisonous.

FORBES: Fact and Comment

And since the early 90s they have installed specialist buoys, tethered to the seabed, which use sonar to provide a near-constant stream of data about the ice above.

BBC: Arctic ice melting at 'amazing' speed, scientists find

You can read the whole backstory about Tacit here: How Trying to Make a Video Game Created Sonar for the Blind.

FORBES: Assistive Technology Device for the Blind