Altitude & Ocean PPO₂ Nomogram — Integrated Hypoxia/Hyperoxia Trainer This interactive visual simulator demonstrates how the partial pressure of oxygen (PPO₂) changes with both increasing altitude and increasing depth. Users can adjust altitude, depth, oxygen fraction, and breathing mode (open circuit, CCR, or pure O₂) to observe real-time PPO₂ values, ambient pressure changes, and corresponding physiological risk zones. By combining high-altitude hypoxia and underwater hyperoxia in a single tool, it bridges two normally separate training contexts, making the concepts of oxygen partial pressure intuitive for divers, climbers, aviators, and rescue professionals. Risk overlays, live numerical readouts, and scenario presets reinforce critical safety thresholds (hypoxic danger <0.16 bar, CNS toxicity risk >1.60 bar) while engaging learners through hands-on exploration. Ideal for use in advanced diving, technical rescue, expedition planning, and cross-environment physiology courses, this nomogram transforms abstract gas-law theory into an immediate, visual understanding of how equipment, environment, and physiology interact.

Drag anywhere in a panel to move the climber or diver. Sliders change oxygen, depth, and altitude. HUDs and the black title labels are draggable; the sidebar resizes (drag the thin bar). PPO₂ decreases with altitude because ambient pressure falls as elevation increases, reducing the partial pressure of inspired oxygen and increasing the risk of hypoxia. PPO₂ increases with depth because ambient pressure rises under water, elevating oxygen partial pressure and increasing the risk of hyperoxia and central nervous system (CNS) oxygen toxicity.