ISO/IEC TR 30167:2021 describes the enabling and driving technologies of underwater communication such as acoustic communication, optical communication, Very Low Frequency (VLF)/Extremely, Low Frequency (ELF) communication, and Magnetic Fusion Communication (MFC). This document also highlights:– technical overview of different communication technologies;– characteristics of different communication technologies;– trends of different communication technologies;– applications of each communication technology;– benefits and challenges of each communication technology.