Animals use acoustics to communicate and explore.  Dolphins and bats use acoustics to hunt and navigate in environments where site is of limited use.  TSR has developed and is developing acoustic tools to explore similar environments in both air and water.  Underwater applications of acoustics are of particular interest because even in daylight vision is limited and other modalities such as radar don’t work at all.  A typical application for underwater acoustics is bathymetry.  Our systems can do this but like the dolphin we are going for more.  We use acoustics to establish an information presence in the water.