Recently, automation and unmanned technologies have been developing rapidly in various industries. In the field of traffic and transportation, the development of unmanned technologies is remarkable, and it is already moving on to the practical stage in the field of transportation infrastructure such as automobiles, railways and aircrafts. The development of automation and autonomy technologies is expected not only to save manpower and reduce labor, but also to eliminate human errors and greatly contribute to ensuring our safety. This paper focuses on our autonomous technology for ships and also introduces the history of our development processes. In view of the greater use of the autonomous technology in society in the future, this innovation is considered to be also used for inspection work on marine infrastructure such as breakwaters and revetment structures. With this notion in mind, we have conducted an experiment to confirm whether our autonomous vehicles are suitable to meet such a purpose. In addition, we describe the expectations, challenges, and prospects for practical applications of the technology in other areas, such as marine traffic and security, as well as inspection applications for marine infrastructure.