We hauled in SUESI yesterday afternoon and began recovering OBEM receivers. We do this by sending a coded acoustic signal to a transducer installed adjacent to the data logger, which triggers a voltage across a small piece of cable known as a burn wire. The voltage corrodes the burn wire and allows the receiver to release from an anchor and float to the surface. The receiver is also equipped with a GPS transponder that lets us know when it is on the surface as well as its current position so we can retrieve it.
We should be done retrieving all of the receivers in the next 36 hours, after which we will transit to the central survey line and repeat the entire process once again!