Arrest of a ship as a provisional measure creates the conditions for future settlement of the claim in a possible later enforcement proceeding. Provisional measures primarily are intended as a means of securing claims, not settlement claims. They only create the conditions for the future so that creditors, later bailiffs, can settle their claim as quickly, easily and favorably as possible. Maritime claims are in practice extremely high amounts, and the provisional ban on departure from seaport and the impossibility of future use of the ship, inflicts enormous losses to operators/owners. It is for these reasons that creditors choose this type of measure to more effectively secure their settlement in subsequent enforcement proceedings or to enforce the obligation. Therefore, when deciding on a proposal for measure, the court must take into account the proportionality of the measure and the protected good. As legal sources in the Croatian national system of regulation the mentioned topic, the Maritime Code is applied primarily, and in the alternative, the Law on enforcement is applied as a subsidiary legal source. At the international level, the topic is regulated by two conventions: International Convention relating to the arrest of seagoing ships 1952 and the Arrest Convention 1999. The paper analyzes: concept and basic features, legal sources, assumptions, maritime claims, which ship can be stopped, guarantee, the possibility of arresting the ship under a contract of affreightment, the jurisdiction, legal remedies and case law.