The increasing migration of population in the world is one of the urgent international problems. Statesmake efforts to counter the illegal migration and to help people seeking asylum. This problem is themost challenging to tackle in the sea. The article reveals the contents of international cooperation and therole of international law in this field. The specific features of tackling illegal migration are analyzed within thevarious marine spaces: in inland waters, in the territorial sea and in the open sea. The issues of internationalcooperation on suffering refugees and other migrants in danger on the sea have been studied as well.International legal and organizational issues facing the world community are introduced and their separate solutions are offered. In the authors’ opinion, the activities of states regarding migrants should be carriedout in compliance with their legal status and particular situation. In any case, the migrants’ status must bedefined not on the sea but on the shore. If some people are in danger, they must be helped notwithstandingthe legal status of the persons being rescued. Measures of criminal liability and other measures accordingto the legislation of states and international commitments must be applied to illegal migration organizers. Itis important that the rules of international law, international organizations and international bodies recommendationsthat deal with the problems of migration should be carried out at the national level by means ofupgrading related laws. It is also important to work out and to upgrade the subordinate regulatory legal actsconcerning the questions of illegal sea migration counteraction, measures taken towards refugees and otherasylum seekers, being present on board of the ships in distress. Accordingly, the issue is to be solved as tothe attitude of states towards the migrants on board of the watercraft that do not comply with the seafaringsecurity requirements that means that they are potentially in danger.