This paper aims at verifying the observation that many speakers of closely related Atlantic English(-lexifier) Pidgin(s) and Creole(s), or EP/C(s), can understand each other. In order to test mutual intelligibility of different EP/Cs, an electronic survey was completed by 56 participants from Ghana, Guyana, and Nigeria. In addition, 20 interviews were conducted with informants representing eight different nationalities and residing in Guyana at the time. The data were also supplemented by a reading comprehension and translation task of short passages in eight Atlantic EP/Cs conducted in Ghana and Guyana. The results of the study indicate that intelligibility exists between most (but not all) language pairs. We therefore suggest that we are dealing with a case of pluriareality rather than pluricentricity, as the habitual criteria for the latter are not (yet) fulfilled. We believe that this can be accounted for by a postcolonial understanding of language variation, allowing for the postulating of a language system with fluid borders for use in wider contexts, including writing. Nevertheless, the postcolonial aspect shall be addressed in more detail in a posterior study.