This book investigates the architectures and characteristics of OUSNs, the mobility models of OUSN nodes, the challenges of message dissemination, and some evaluation indexes of message dissemination. Then, this book provides some message dissemination techniques in OUSNs from the viewpoints of nodes and data messages, respectively. The proposed message dissemination techniques and their conclusions can provide some useful insights to improve the performance of data message dissemination and promote the future applications of OUSNs. Researchers and engineers in the field of underwater sensor networks can benefit from the book.