Deep Autonomous Profiler (DAP) Lander

The Deep Autonomous Profiler (DAP) Lander was designed to collect water samples at various ocean depths to determine physical oceanographic properties, seawater composition, and biological communities of the deepest places in the world’s oceans. The DAP has been used in the deep waters of the Puerto Rico trench (8300m), where water samples were radiocarbon-dated to help estimate the turnover time and origin of the trench water.  

Owned and operated by the University of Rhode Island’s Graduate School of Oceanography, the DAP can carry up to 24 Niskin bottles to sample large quantities of water throughout the water column. Additionally, up to four pressure-maintaining sample bottles (provided by the Scripps Institution of Oceanography) allow samples to stay at high pressure. The DAP is also able to make its own sampling decisions.  The vehicle will record data on the descent to the seafloor and then process those data to determine which depths it should collect water samples on the return trip to the surface.  This capability allows the user to make requests such as collecting a sample at the oxygen minimum depth without needing to know that specific depth ahead of time.