Maritime Object Tracking Technology or MOTT. Image courtesy US Coast Guard RDC

Marine Link has a story about the Coast Guard Research and Development Center (RDC), including the origin of the devices in the photo above. In addition to making the position of jettisoned contraband, I presume they might also be useful in the case of a man overboard.

They are also working on sense and avoid capabilities to allow over the horizon operation of small UAS that can be operated from units without a flight deck, and there is more.