Scuba Diving International (SDI) Computer Nitrox Practice Exam

What are two reasons why EAN 32 is a good choice for Nitrox diving?

1. Higher risk of oxygen toxicity and increased bottom time

2. Longer bottom time and less risk of oxygen exposure

3. Better visibility and reduced costs

4. Less buoyancy control and more ascents

The correct answer is: Longer bottom time and less risk of oxygen exposure

The choice highlighting longer bottom time and less risk of oxygen exposure accurately reflects the benefits of using EAN 32 (Enriched Air Nitrox with 32% oxygen) for diving. When divers use a nitrox mix such as EAN 32, the higher proportion of oxygen compared to air allows them to extend their bottom time at certain depths without significantly increasing the risk of nitrogen narcosis. This is particularly advantageous for recreational diving, where extended exploration and prolonged enjoyment of underwater environments are desired. Additionally, using EAN 32 reduces the risk of oxygen toxicity, especially at depths up to approximately 30 meters (100 feet), because the partial pressure of oxygen is lower than in pure oxygen scenarios or in deeper diving with higher nitrogen levels. This lower risk allows divers to plan longer dives safely, enhancing their overall diving experience. These benefits, particularly in terms of time and safety, make EAN 32 a preferred choice for many divers when planning Nitrox dives.