Underwater communication systems, underwater speakers, underwater microphone assemblies and associated methods are described. According to one aspect, an underwater speaker includes a housing, a transducer member coupled with the housing and positioned to contact a body of water, wherein the transducer member is configured to vibrate to generate sound pressure waves within the body of water which comprise content which is audible to humans within the body of water, and an exciter coupled with the transducer member and configured to impart forces to the transducer member to cause the vibration of the transducer member to generate the sound pressure waves in the body of water as result of a received electrical signal which comprises the content.