Proposing ‘the littoral’ as a subject of historical enquiry, this article centres on British rule over the waters, isles, and shores in nineteenth-century colonial Hong Kong. It argues that similar and connected to its rule over urban space, the British government endeavoured to regulate the colony’s watery fringes out of racial and other concerns. Commensurate with the growth of shipping, colonial rulers demarcated particular littoral spaces as mirrors or even extensions of land spaces. In the late nineteenth century, an emerging hierarchy of delineated navigational, anchorage, and quarantine spaces was discernible in Hong Kong’s littorals. Despite their efforts to structure littoral space, British colonial authorities failed to direct its actual usage. Not only did stakeholders compete and negotiate over using Victoria Harbour, but also, many Chinese watercraft countered official control by venturing across administrative boundaries. More broadly, the case of Hong Kong suggests perspectives for addressing the complexity of the littoral history of colonial port cities in Asia. First is the examination of connections between different areas within littoral space. Second is the inseparability between littoral space and urban space in terms of government policies. Third is the contrast between colonial designs and actual negotiations regarding the use of littoral space.