Along with the development of communications technology including satellite as well as the development of robots that work underwater, various marine technologies have emerged in the era of the fourth industrial revolution. Competition among new industries has been intensified along with the implementation of cutting-edge technologies. Unmanned ship is one of the examples. It enables sailing without a sailor when setting a sea route through a program. Also, it can reduce labor costs and minimize the possible damage of property and human life. Moreover, a robot that can explore the deepest seafloor was developed and it has grabbed a lot of attention in the field. And a robot that can inhale the marine litter was also developed and it is expected to bring a positive impact on the domestic marine industry. On Smart Korea, we look into the ongoing development of cutting-edge marine technologies.