This paper introduces the development of an acoustic underwater glider integrated with an underwater acoustic modem designed to enable the real-time transmission of ocean observation data. The glider features three sequentially connected, independent compartments and is capable of operating at depths exceeding 1000 m. To ensure stable communication, two acoustic transducers are mounted at the rear of the glider and optimized to maintain a consistent energy radiation angle despite variations in the glider's attitude. The acoustic modem, housed within one of the compartments, operates with a standby power consumption as low as 5 mW, significantly enhancing the overall energy efficiency of the system. To address the glider's motion dynamics and the unique characteristics of the underwater acoustic channel, a multi-carrier frequency shift keying-based underwater acoustic communication scheme combined with a Stop-and-Wait Automatic Repeat Request protocol was designed and implemented. The system's performance and reliability were validated through sea trials conducted in the South China Sea. The results demonstrated that the glider achieved reliable underwater acoustic communication over distances of up to 5 km. This research highlights the potential of the acoustic underwater glider for applications such as underwater acoustic measurements and distributed networking collaboration. The system holds significant promise for advancing underwater acoustic communication and ocean observation technologies.