Scuba Diving International (SDI) Computer Nitrox Practice Exam

How does diving with Nitrox affect dive tables compared to air?

1. Dive tables remain the same

2. Dive tables require adjustments

3. Diving with Nitrox is not allowed

4. Dive tables are irrelevant

The correct answer is: Dive tables require adjustments

Diving with Nitrox does require adjustments to dive tables compared to standard air diving. This is primarily due to the differences in the gas mixture and its effects on nitrogen absorption in your body during a dive. Nitrox, which is a mixture of oxygen and nitrogen, has a higher percentage of oxygen compared to regular air, which consists of approximately 21% oxygen and 79% nitrogen. The increased oxygen in Nitrox allows divers to extend their no-decompression limits and reduce nitrogen exposure, potentially decreasing the risk of decompression sickness. As a result, specific tables or dive computer settings for Nitrox dives must be used, which account for the different gas mixture and its properties. These adjustments in dive tables are crucial for planning dives safely, to ensure that divers avoid exceeding limits that could lead to dangers associated with nitrogen buildup in the body. Considering this context, it's clear why the dive tables need to be modified for Nitrox, making this choice the correct answer.