Final answer:
Limiting dive time to 30 minutes is not the primary way to avoid air emergencies; proper planning, air supply monitoring, and understanding of personal air consumption rates are crucial.
Step-by-step explanation:
The statement that the primary way to avoid low-on-air or out-of-air emergencies on a deep dive is to limit dive time to 30 minutes is false. While limiting dive time can help conserve air, it is not the primary strategy for avoiding such emergencies. The main ways to prevent running low or out of air involve careful planning and monitoring of air supply, as well as understanding and managing one's air consumption rate throughout the dive. Scuba divers must be trained in calculating the air consumption, understanding the effects of greater depths on air supply, and using dive computers or tables to track nitrogen absorption and remaining dive time. The primary way to avoid low-on-air or out-of-air emergencies on a deep dive is not by limiting dive time to 30 minutes. Instead, divers typically manage their air supply through proper dive planning, monitoring air consumption, and adhering to safe diving practices. This may include calculating and respecting no-decompression limits, ascending with sufficient air reserve, and utilizing safety stops. Proper training, equipment maintenance, and adherence to dive protocols are crucial for ensuring a safe and enjoyable diving experience. Simply limiting dive time without considering other factors may not be an effective or safe approach.