Austria and Italy have recently proposed that processing the protection claims of asylum seekers attempting to cross the Mediterranean should take place aboard government vessels at sea. Shipboard processing of asylum claims is not a novel idea. The policy has been used for many years by the governments of the United States and Australia. This article examines the relevant international law, as well as State practice and domestic jurisprudence in the United States and Australia, to explore whether shipboard processing complies with international refugee and human rights law. It concludes that, while it may be theoretically possible for shipboard processing to comply with international law, there are significant practical impediments to carrying out shipboard processing in a manner that is compliant with the international obligations of States. Current practices in the United States and Australia fall short of what is required. Nor is there any indication that the Austrian/Italian proposal would contain the required safeguards. It is argued that this is by design. The appeal of shipboard processing for governments is that it allows them to dispense with the safeguards that asylum seekers would be entitled to if processed on land. Best practice is for all persons interdicted or rescued at sea to be transferred to a location on land where they have access to effective status determination procedures and are protected from refoulement and unlawful detention.