RAFOS float

A RAFOS float is a submersible device used to map ocean currents in a Lagrangian way. It is a self-sustaining device using the SOFAR (SOund Fixing And Ranging) channel as a wave-guide for sound, allowing it to determine its position as a function of time. It derives from SOFAR floats, which emitted from the ocean to moored receivers, but instead receives the signals from the moored devices, thus allowing a much lower fabrication cost. That is why it is called RAFOS: it is SOFAR spelled backwards.