79I4 B
 Which of the following conditions does not typically impair Inmarsat-B communications ?
A. An obstruction, such as a mast, blocking the signal between the satellite and the SES antenna when the vessel is steering a specific course. 
B. Normal precipitation from gales and storms. 
C. A satellite whose signal is on a low elevation, below the horizon. 
D. Travel beyond the effective radius of the satellite.
