This paper delves into the unexplored area of Advance Directives (ADs) in maritime surroundings, diving into the moral and legal quandaries that crop up when these directives are used at sea. ADs, which include durable powers of attorney and living wills, are essential documents that indicate a person’s wishes for healthcare in the event of incapacitation. Global variations in legal recognition pose ethical questions, particularly in non-regulated jurisdictions. The maritime context introduces unique challenges, questioning the ethical applicability and binding of ADs at sea. Despite international and European laws ensuring medical assistance, the absence of specific provisions for ADs raises uncertainties. The paper advocates for a balanced approach respecting autonomy while addressing practical challenges, proposing solutions and a standardized international framework. This exploration seeks to uphold individual healthcare preferences, whether on solid ground or navigating the open sea.