Editorial of the Special issue of underwater robotics

Communication: Wireless communication is very limited underwater. In difference to land-based roboticswe cannot use out of the box solutions likeWi-Fi communication to connect robots, devices and operators. In the recent years, acoustic modems have made good progress and could be considered as state of the art, but, an online video communication still requires a cable link. Further concepts are required either or improve underwater communication or to avoid communication. The latter needs an increase of autonomy of systems.