Shakespeare Marine Antenna Extension - 1 Shakespeare extension masts can be used to extend the reach of smaller marine antennas by increasing their height above the water, or by helping them clear obstructions that would otherwise interfere with proper radiation. Shorter masts are useful for mounting marine TV antennas, GPS receivers, marine satellite TV dishes and the like. Shakespeare Style 4364 Extension Mast 1 long White molded polycarbonate Standard 1-14 threads, male upper, female lower On