C-Band requires larger VSAT antennas ranging from 2.4m - 3.8m.
C-Band is used by vessels that move frequently from region to region making lower priced, regional Ku-Band coverage impractical due to having to switch beams more often, and traverse ocean areas where Ku-band coverage is unavailable.
A global C-Band beam covers about 1/3rd of the globe, which is all the area visible from the satellite. The whole world can be covered with 3 global beam satellites.
Intelsat’s Network Broadband Maritime Service
C-Band satellites often also have hemi beams (half the visible globe) and zone beams which provide higher signal strengths in certain areas.