Underwater wireless communication systems are becoming a priority in terms of research and technological development due to the increasing demand for exploring the oceans potential in scientific target fields like pharmaceutical, oil, minerals, environmental and biodiversity. This demand is increasing exponentially with the need for high data rate and near-real-time communications between submerged mobile and static agents. In this work, a high data rate communications system that works at 1 Mbps has been developed. For high data-rates and real-time applications it was necessary to develop ultrasound transducers able to work at high frequencies, and wideband, with suitable responses to digital modulations. The system was validated by the implementation of a full duplex point-to-point communication at 1 Mbps using OOK modulation with a 1 MHz single carrier. The system was successfully tested in a swimming pool at a distance of 6 meters with a 1 Mbps rate, using just 1.4 µJ of energy consumption per bit.