Theory suggests that matching self-talk to sport demands can result in performance benefits, but the effects of self-talk in adventure-sport contexts that feature high risk (e.g., self-contained underwater breathing apparatus [SCUBA] diving) have not been studied. This research explored the effects of instructional and motivational self-talk in a high-risk adventure-sport context. Students (N = 78) enrolled in SCUBA diving courses were randomly assigned to self-talk (instructional, motivational) or control conditions; practiced self-talk and SCUBA diving skills; rated their levels of effort, confidence, and focus; and were evaluated during certification dives. Results indicated that participants gained confidence over time. The instructional-self-talk group reported being significantly more focused and confident during certification dives than the motivational-self-talk group. These results demonstrate the efficacy of matching self-talk to task demands in the high-risk context of adventure sports.