With the increase in ocean exploitation and exploration，the Underwater Internet of Things(UIoT) integrating multiple technologies for smart ocean investigation has created a research trend，and the use of computationally efficient and generalized algorithms for azimuth estimation is the current trend. To meet the above requirements，in this paper，we propose a novel and widely-used centrosymmetric array of the Unitary Quaternion (UQ)model，where the estimation and decomposition of the corresponding covariance matrix can be performed in the real domain instead of the complex domain，thus achieving low computational complexity. In addition，we analyze the physical implications of the model and combine it with the emerging quaternion-based attitude estimation and control to reveal the potential advantages of the UQ model in UIoT. In simulation experiments，we have demonstrated the flexibility and applicability of the UQ model by testing the performance of the algorithm in several simulated underwater scenarios.
