Acoustic waves are widely accepted as the most suitable means of communicating underwater, since radio waves suffer from severe attenuation through water. Although they can be transmitted over long distances, they face significant challenges which make the development of communication networks difficult. Fundamental constraints include long and variable propagation delays if transmitting nodes are located at different distances from a receiver. This PhD will explore the potential of using techniques adopted in geostationary satellite communication systems, given similarity with respect to the long propagation delays. Simulation based modelling and performance evaluation will be undertaken, backed up by mathematical analysis, for typical scenarios. New protocols will be designed to mitigate against the long and variable propagation delays in order to maximise the use of the available capacity.