PADI Deep Diving Techniques & Planning 2 — Questions and Answers
Question 1: When planning a deep dive to 100 feet, which factor most critically determines your maximum bottom time?
- Water temperature
- No-decompression limit (NDL) (Correct answer)
- Visibility conditions
- Current strength
Correct answer: No-decompression limit (NDL)
The no-decompression limit (NDL) defines the maximum time you can spend at depth without requiring mandatory decompression stops.
Question 2: What is the recommended maximum ascent rate during a deep dive?
- 60 feet per minute
- 30 feet per minute (Correct answer)
- 100 feet per minute
- 45 feet per minute
Correct answer: 30 feet per minute
PADI recommends an ascent rate of no faster than 30 feet (9 meters) per minute to allow dissolved gases to safely off-gas.
Question 3: A diver at 100 feet suddenly feels task-loaded and anxious. What is the MOST likely contributing factor?
- Hypothermia onset
- Nitrogen narcosis (Correct answer)
- Oxygen toxicity
- Carbon dioxide buildup from skip-breathing
Correct answer: Nitrogen narcosis
Nitrogen narcosis commonly causes anxiety, impaired judgment, and task-loading difficulty at depths around 100 feet and beyond.
Question 4: During pre-dive planning for a deep dive, what rule governs how you divide your air supply?
- The rule of thirds (Correct answer)
- The 50/50 rule
- The rule of halves
- The 25% reserve rule
Correct answer: The rule of thirds
The rule of thirds allocates one-third of gas for the outward journey, one-third for return, and one-third as an emergency reserve.
Question 5: Which condition is a contraindication for deep diving and requires medical evaluation before participation?
- Mild sunburn
- A history of spontaneous pneumothorax (Correct answer)
- Mild seasickness
- Recent ear infection that has fully resolved
Correct answer: A history of spontaneous pneumothorax
A history of spontaneous pneumothorax indicates a risk of lung over-expansion injury under pressure changes, requiring physician clearance.
Question 6: What is the PRIMARY reason deep divers should carry an audible and visual surface signaling device (DSMB)?
- To mark the dive site for navigation
- To signal their position to surface support when surfacing far from the boat (Correct answer)
- To scare away marine life
- To measure ascent rate
Correct answer: To signal their position to surface support when surfacing far from the boat
A DSMB allows divers who surface away from the entry point to be easily spotted by boat traffic and surface support personnel.
Question 7: On a deep dive profile, what is the purpose of a safety stop at 15 feet for 3 minutes?
- To equalize ear pressure before surfacing
- To allow additional nitrogen off-gassing and reduce DCS risk (Correct answer)
- To check buoyancy before entering the boat
- To conserve remaining air supply
Correct answer: To allow additional nitrogen off-gassing and reduce DCS risk
A safety stop at 15 feet provides extra time for dissolved nitrogen to off-gas, significantly reducing the risk of decompression sickness.
PADI Deep Diving Techniques & Planning 2
When planning a deep dive to 100 feet, which factor most critically determines your maximum bottom time?