  The next generation of wireless communication systems will integrate
terrestrial and non-terrestrial networks targeting to cover the undercovered
regions, especially connecting the marine activities. Unmanned aerial vehicles
(UAVs) based connectivity solutions offer significant advances to support the
conventional terrestrial networks. However, the use of UAVs for maritime
communication is still an unexplored area of research. Therefore, this paper
highlights different aspects of UAV-based maritime communication, including the
basic architecture, various channel characteristics, and use cases. The
article, afterward, discusses several open research problems such as mobility
management, trajectory optimization, interference management, and beamforming.
