The development of the smart ocean requires that various features of the ocean be explored and understood. The Underwater Internet of Things (UIoT), an extension of the Internet of Things (IoT) to the underwater environment, constitutes powerful technology for achieving the smart ocean. This article provides an overview of the UIoT with emphasis on current advances, future system architecture, applications, challenges, and open issues. The UIoT is enabled by the most recent developments in autonomous underwater vehicles, smart sensors, underwater communication technologies, and underwater routing protocols. In the coming years, the UIoT is expected to bridge diverse technologies for sensing the ocean, allowing it to become a smart network of interconnected underwater objects that has self-learning and intelligent computing capabilities. This article first provides a horizontal overview of the UIoT. Then, we present a five-layer system architecture for the future UIoT, which consists of a sensing, communication, networking, fusion, and application layer. Finally, we suggest the current challenges and the future UIoT research trends, in which cloud computing, fog computing, and artificial intelligence are combined.

中文翻译：

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智能海洋中的水下物联网：系统架构和开放性问题

智慧海洋的发展要求探索和理解海洋的各种特征。水下物联网（UIoT）是物联网（IoT）对水下环境的扩展，它构成了实现智能海洋的强大技术。本文提供了UIoT的概述，重点介绍了当前的进步，未来的系统架构，应用程序，挑战和未解决的问题。UIoT受自动水下航行器，智能传感器，水下通信技术和水下路由协议的最新发展的支持。在未来的几年中，UIoT有望在传感海洋的各种技术之间架起桥梁，使其成为具有相互学习功能和智能计算功能的互连水下物体的智能网络。本文首先提供了UIoT的横向概述。然后，我们提出了面向未来UIoT的五层系统架构，该架构由传感，通信，网络，融合和应用层组成。最后，我们提出了云计算，雾计算和人工智能相结合的当前挑战和未来的UIoT研究趋势。