Assistant Professor of Private Law, South Tehran Branch, Islamic Azad University, Tehran, Iran

In the voyage charters to avoid delay in loading and unloading operations as a demurrage. A condition is included as demurrage, based on which the charterer undertakes to carry out loading and unloading operations within a specified period (lay time). The closest reference to demurrage in civil law should be considered as 'penalty clause'. In various legal systems there are various theories about the nature of demurrage; Including contractual penalties, complementary freights, damages that results in important results of each of these theories, and a detailed understanding of the nature of demurrage, helping to find demurrage rules, and determining the nature of demurrage is the source of important works, so it should not be considered as a theoretical issue. During the voyage, there are various damage to each of which are compensated for. In this article, while addressing various aspects of the matter, the nature of demurrage and types of marine damages will be discussed and investigated.