Abstract: A new surface drifting buoy with sub-meter positioning accuracy is developed based on real-time array calibration (RAC) technology, aiming to resolve the contradiction between high-precision observation and low-cost implementation in deep-sea environments. By constructing a spatiotemporal synchronization calibration model of a distributed observation array, the proposed technology eliminates reliance on external augmentation signals while achieving high-precision positioning. During the buoy development, the three-dimensional potential flow theory is adopted for hydrodynamic analysis and structural optimization of the buoy body. A highly reliable data acquisition unit is designed using the low-power STM32F407 embedded chip, and a multi-terminal visual data management platform is built by integrating B/S and C/S hybrid architecture with mainstream front-end and back-end frameworks. South China Sea trials demonstrate that during the continuous observations of 112 days and 66 days, the data acquisition rates of the two prototypes reach 96.66% and 98.18%, respectively, and the horizontal positioning accuracy is better than 0.6 m, thereby validating the stability and reliability of the buoy in deep-sea environments.