This article considers theoretical aspects of the non-belligerent and political use of naval forces, commonly described as naval diplomacy. It presents four arguments. Firstly, it criticises the often used term "gunboat diplomacy" for being too narrow, emotionally charged, and burdened by colonialism. Secondly, the theories on naval diplomacy are criticised for being better suited for doctrinal purposes than for analytical purposes. Thirdly, criticism is levelled against the term "naval presence," which is deemed insufficient as a focal point in a theory of naval diplomacy. Fourthly, elements of a workable theory of naval diplomacy are presented, including the political aim, naval means, diplomatic method, and geopolitical context. In conclusion, warships and navies are described as symbols of national sovereignty and power, and for having, not only a defence value, but also a symbolic, supportive, and coercive value.