Underwater acoustic communications operates in a very challenging transmission environment. The channel undergoes rapid changes, exacerbated by vehicle movement, turbulence, and gravitational surface waves. The channel also experiences significant frequency selectivity. This favors the use of OFDM-based signaling, and HCDC has developed novel frequency-domain doppler and multi-path estimators and compensation. Our expertise in dynamic channel estimation and equalization, as well as advanced signal synchronization is directly applicable to acoustic communications. We are working with Dalhousie’s research centers, UMDCC (www.umdcc.ca) and the IORE (www.iore.ca) to transition cutting-edge research into pre-competitive prototypes.