A downcomer for conveying wastewater from an upper level of a marine vessel to a lower level of the marine vessel includes a pair of spaced apart mounting portions and an elongate impact portion extending between the mounting portions. The die hole includes: an entry portion having a cross section monotonically decreasing along a conductor insertion direction; and a coating portion including at least a sub-portion having a constant cross section. The device identification string includes an optional feature component associated with the external device. The nanoprobe instrument includes zone plate optics for focusing and imaging. The receiver unit interprets the overhead data and uses it for controlling and managing the payload data in the system.