This work presents a new perspective on the role of States as reciprocal trustees for the Oceans Public Trust. The concept of the oceans and navigable waters as held in public trust is examined from its origins in the 17th century North Sea fisheries controversy with particular regard to the arguments by Selden and Grotius pertaining to State jurisdiction over oceans and marginal sea areas. Those arguments manifest an underlying common principle of navigational freedom reflected in the parallel public trust development of public rights to fishing and navigation as protected and preserved...