the purpose of this study was to determine the effectiveness of the environmental communications contained in novice certification course manuals. this was accomplished by reviewing the effectiveness of these communications across three certifying bodies, the british sub aqua club (bsac), the professional association of diving professionals (padi) and scuba schools international (ss i), using the framework of the elaboration likelihood model of persuasive communication (petty, mcmichael & brannon, 1 992), and its associated message delivery styles, as a framework for evaluation.the messages conveyed to scuba divers through each agency' s novice certification course manual were analyzed using software-assisted content analysis. the content analysis examined the manifest and latent content to determine the overt and covert messages inherent within the texts. this was accomplished using a mixture of inductive emergent category development and deductive category application. images were also coded to indicate whether they supported or contradicted the environmental messages espoused in the manual. all written messages were assigned codes that indicated the message delivery style, and route to persuasion, used. once each certifying bodies' textbook had been systematically coded, and categories i themes had been identified, a comparison of the environmental messages communicated across certifying bodies was undertaken to determine the manuals' relative efficacies.