PADI Underwater Navigation & Skills 2 — Questions and Answers
Question 1: When using a compass underwater, what does 'reciprocal heading' mean?
- The heading directly opposite your current bearing (180° away) (Correct answer)
- A heading adjusted for current drift
- The magnetic declination correction for your dive site
- The bearing you swim after completing a square pattern
Correct answer: The heading directly opposite your current bearing (180° away)
A reciprocal heading is exactly 180° opposite your outbound bearing, used to return to your starting point.
Question 2: You're navigating a square pattern and need to make four 90-degree turns. After your first right turn, which direction should your second turn be?
- Right again (Correct answer)
- Left
- Straight
- Depends on current direction
Correct answer: Right again
A square pattern requires four consecutive 90-degree turns in the same direction (all right or all left) to complete the square.
Question 3: What is the primary limitation of a magnetic compass when diving near certain underwater structures?
- Metal objects and iron-rich rock can cause magnetic deviation (Correct answer)
- Salt water reduces the compass needle's sensitivity
- Pressure at depth distorts the compass housing
- Thermoclines cause the needle to spin erratically
Correct answer: Metal objects and iron-rich rock can cause magnetic deviation
Ferrous metal structures such as shipwrecks or iron-rich volcanic rock can deflect a compass needle, causing inaccurate readings.
Question 4: During an underwater navigation exercise, your kick cycle count suggests you've traveled 30 meters, but your compass shows you've been swimming with current assistance. What should you do?
- Adjust your estimated distance to account for the current's added push (Correct answer)
- Ignore the current since kick cycles are always accurate
- Surface immediately and restart
- Switch to a natural navigation landmark instead
Correct answer: Adjust your estimated distance to account for the current's added push
Current assistance means you cover more distance per kick cycle, so your actual distance traveled is greater than the kick-count alone suggests.
Question 5: Which natural navigation cue is MOST reliable for maintaining a consistent heading in open water with good visibility?
- Sun position and shadow patterns on the bottom (Correct answer)
- Water color changes
- Temperature gradients
- Fish schooling direction
Correct answer: Sun position and shadow patterns on the bottom
Sun angle and shadow patterns on the sandy bottom provide a consistent, broad reference for maintaining direction in clear, shallow water.
Question 6: A diver wants to search a rectangular area using a lawn-mower pattern. What determines the width of each search lane?
- The visibility distance, so adjacent lanes overlap slightly (Correct answer)
- The diver's fin span
- The depth of the dive
- The strength of the current
Correct answer: The visibility distance, so adjacent lanes overlap slightly
Lane width in a lawnmower pattern is based on visibility range, with slight overlap to ensure no area is missed.
Question 7: What does it mean if your compass lubber line is not aligned with your body when navigating?
- You will swim at an angle to your intended heading, causing course error (Correct answer)
- Your depth gauge will read incorrectly
- The compass will stop functioning
- Your buoyancy will be affected
Correct answer: You will swim at an angle to your intended heading, causing course error
The lubber line must point in your direction of travel; misalignment means you follow a different heading than the compass indicates.
PADI Underwater Navigation & Skills 2
When using a compass underwater, what does 'reciprocal heading' mean?