Evaluating tablet-based cognitive testing in underwater environments: a case study with two divers

Abstract Operating various devices is a critical skill for scuba divers. With recent technological advances, the demands and complexity of underwater device operation have increased, highlighting the importance of investigating human-device interactions on perception and movement. Recently, the waterproof tablet has enabled underwater human research. However, the potential applications and limitations of the waterproof tablet for underwater research have not been thoroughly examined. This case study, involving two divers, examined the feasibility and limitations of using the waterproof tablet to conduct cognitive tasks in underwater environments, focusing on methodological and practical challenges. Two divers performed a visual search task and a gradual-onset continuous performance task (grad-CPT) in both land-based and underwater conditions (at a depth of 6 m), and their performance was compared across environments. The results suggested that the waterproof tablet is a viable tool for conducting cognitive tasks underwater, as task performance resembled typical laboratory results. However, several issues were identified, including limitations in stimulus presentation and concerns regarding the reliability of touch responses. Our case study provides foundational data for designing future tablet-based experiments in underwater and other extreme environments.