Argo Ocean Profilers
URL = http://www.argo.ucsd.edu
"Argo ocean profilers. You may have never heard about this, but in every sea, there is at least one floating scientific instrument that floats for a few hours on the surface, than dives up to 2000m where it stays for usually around 10 days, surfacing again for a few hours, transmitting information to satellite such as the temperature, salinity, sometimes pH and several other environmental variable at different depth. There is more than 3500 of these "mini submarines" in operation today. It took 25 years to develop this network of environmental sensors, but it is our most precious instrument to understand geochemistry, climate change, sea level rising and many other changes of our planet. The technology is developed by a large international scholar consortium, the information it produces is in near-real time and accessible for free."