Background and Theoretical Foundations: The traditional military technologies and methods at sea have undergone many changes since the approval of naval Warfare documents and have developed in such a way that they will transform future naval wars, and these developments necessitate the transformation of rights. It leads to a naval war. Cyber war has been accepted as one of the methods of war along with other land, sea, air, and space methods, but the difference between this method and other methods is that each of the mentioned territories can be used as a base to carry out a Cyber-attack. The emergence of Cyber capabilities in the sea means that naval forces are always more connected which leads to greater vulnerability at sea. The purpose of this brief is specifically to examine the Cyber-attack at sea from the perspective of the law of maritime armed conflicts. Therefore, the ability to apply international humanitarian law and the rules governing the law of maritime Warfare in the case of a Cyber-attack at sea will be interpreted and investigated.Methodology: The research method of this article is descriptive and analytical, and the process of collecting library information is reference, by referring to sources through books, documents, periodicals, and the Internet, we obtain research data. Findings and conclusion: The findings of the research indicate many ambiguities in applying the law of maritime conflict to maritime Cyber Warfare, but humanitarian law can be used with all modern tools, which has been supported by the International Committee of the Red Cross in recent decades.