SDI Open Water Scuba Diver Practice Exam

At what water temperature does your body begin to need thermal protection?

1. 78 degrees

2. 82 degrees

3. 86 degrees

4. 90 degrees

The correct answer is: 86 degrees

The body begins to need thermal protection when water temperatures drop to around 86 degrees Fahrenheit. At this temperature, many divers start to experience heat loss, especially during longer dives. The human body loses heat more quickly in water than in air, and as the water temperature decreases, the risk of hypothermia and discomfort increases. When water temperatures are at or below this level, it becomes essential to utilize thermal protection such as wetsuits or drysuits to help maintain body warmth. This is particularly important for divers who may be submerged for extended periods or those who are not accustomed to cooler water temperatures. In contrast, water temperatures above 86 degrees generally do not pose a significant risk of heat loss, allowing divers to dive without thermal gear more comfortably. Thus, recognizing the importance of thermal protection at 86 degrees is crucial for maintaining safety and comfort during scuba diving activities.