Scuba Diving International (SDI) Computer Nitrox Practice Exam

Why is it important for team members to use the same Nitrox mixture?

1. To simplify equipment checks

2. To avoid violating maximum PO2 limits during dives

3. To match dive computer settings

4. To increase dive duration

The correct answer is: To avoid violating maximum PO2 limits during dives

Using the same Nitrox mixture among team members is crucial primarily because it helps avoid violating the maximum partial pressure of oxygen (PO2) limits during dives. Different Nitrox mixtures have distinct oxygen percentages, which directly influence the maximum allowable depths for safe diving. If divers utilize varied mixtures, one could inadvertently expose themselves to higher PO2 levels than recommended, leading to potential oxygen toxicity and other related risks. In a team diving scenario, maintaining uniformity in the Nitrox blend not only ensures that every diver can safely manage their dive profiles but also allows for cohesive planning regarding depth limits, bottom times, and ascent procedures. This synchronization helps prevent unexpected scenarios where one diver may be limited by their gas mixture while another is not, thereby reducing risks associated with discrepancies in dive planning and execution. While simplifying equipment checks, matching dive computer settings, and increasing dive duration are all important considerations in diving, they are secondary to the fundamental safety issue posed by varying Nitrox mixtures and the associated risks of exceeding maximum PO2 limits.