Before revision: The floats are able to detect the pongs at ranges of hundreds of kilometers because they generally target a range of depths known as the SOFAR ( SOund Fixing And Ranging) channel, which acts as a waveguide for sound.
After revision: The floats are able to detect the pongs at ranges of hundreds of kilometers because they generally target a range of depths known as the SOFAR ( Sound Fixing And Ranging) channel, which acts as a waveguide for sound.