This paper uses a Corpus Pragmatic method to study verbal maritime communication by sorting impulsive professional discourse discerned in co-operative full-mission simulation exercises into the illocutionary points of commissives and directives according to Searle's original classification. Between-group assays of speech acts by native and non-native English speakers are executed and potential miscommunication classed and collated. The Osgood-Schramm communication is used to distinguish between-group odds by native and non-native English speakers. Categories are produced for recognizing speech acts holding no risk, residual risks or high risks of miscommunication.