On the challenge of underwater acoustic communication at short range

It is a persistent misunderstanding that underwater acoustic communication at short range is always easier than at long range. Same for (quasi) stationary configurations being always easier than dynamic ones. This paper gives examples of high-rate links in very shallow water at several kilometres distance, as well as difficult communication conditions in a harbour at a few hundred metres distance. Other previously reported experiments revealed challenging channels between a bottom node and a surface platform floating on the waves, whereas the present study demonstrates excellent connectivity between a bottom node and an underwater vehicle at full speed.