PADI Underwater Navigation and Buoyancy Control 2 — Questions and Answers
Question 1: What is the primary function of a Buoyancy Control Device (BCD) during a dive?
- To provide thermal protection in cold water
- To allow a diver to control buoyancy at any depth (Correct answer)
- To hold diving instruments and accessories
- To protect the diver from physical injury
Correct answer: To allow a diver to control buoyancy at any depth
A BCD allows a diver to add or release air to achieve neutral, positive, or negative buoyancy at any point during the dive.
Question 2: A diver who consistently sinks feet-first in the water likely has too much weight placed where?
- On the weight belt at the front
- On the weight belt at the hips or ankles (Correct answer)
- In the BCD trim pockets at the back
- In the tank band
Correct answer: On the weight belt at the hips or ankles
Excess weight on the hips or ankle weights pulls the lower body down, creating a feet-first or head-up angle that increases drag.
Question 3: What is the correct method to check if a diver is wearing the proper amount of weight before a dive?
- Submerge completely and see if you sink to the bottom
- Float at the surface with a full breath, eyes at water level, and a nearly empty tank (Correct answer)
- Descend to 15 feet and see if you sink or rise
- Check weight against manufacturer's chart based on body weight
Correct answer: Float at the surface with a full breath, eyes at water level, and a nearly empty tank
A diver is properly weighted when they float at eye level with a normal breath and a near-empty tank at the surface.
Question 4: Which technique helps a diver maintain neutral buoyancy when breathing during a dive?
- Inflate the BCD fully during each inhale
- Use a steady, controlled breathing rhythm and avoid breath-holding (Correct answer)
- Deflate the BCD completely and rely on breath control alone
- Exhale rapidly to descend and inhale slowly to rise
Correct answer: Use a steady, controlled breathing rhythm and avoid breath-holding
Maintaining a slow, controlled breathing rhythm allows small buoyancy adjustments through lung volume without excessive BCD inflation.
Question 5: What should a diver do if they experience uncontrolled ascent due to over-inflation of the BCD?
- Grab a rock or coral to stop the ascent
- Swim downward aggressively and dump air from the BCD immediately (Correct answer)
- Remove the weight belt to control the ascent
- Hyperventilate to equalize pressure
Correct answer: Swim downward aggressively and dump air from the BCD immediately
The correct response to uncontrolled ascent is to immediately dump air from the BCD and use a flared body position while swimming downward to slow the ascent.
Question 6: Why is it important to add air to the BCD in small bursts rather than large continuous inflations?
- To preserve air supply in the tank
- To prevent the BCD bladder from overinflating and rupturing
- To avoid ear equalization problems
- To prevent sudden, rapid buoyancy changes that are difficult to control (Correct answer)
Correct answer: To prevent sudden, rapid buoyancy changes that are difficult to control
Adding air in small bursts allows the diver to make incremental buoyancy adjustments and avoid sudden positive buoyancy surges that are hard to control.
PADI Underwater Navigation and Buoyancy Control 2
What is the primary function of a Buoyancy Control Device (BCD) during a dive?