Current MUSs typically employ separate systems for sensing and communication. Due to the limited underwater bandwidth, such a separated architecture leads to spectral fragmentation, while any spectral overlap tends to cause mutual interference, ultimately compromising operational robustness. To mitigate these issues, this chapter explores the design of fully shared integrated waveforms for joint sensing and communication. In order to accommodate heterogeneous MUS nodes, two types of integrated waveforms are developed: a communication-centric shared waveform and a detection-centric shared waveform. Based on these designs, a modular integrated hardware platform with an end-to-end processing chain is implemented. Comprehensive simulations and experimental evaluations are conducted to validate the effectiveness and engineering feasibility of the proposed approach.