Wreck & Cave Diving Fundamentals Flashcards

In cave diving, the 'rule of thirds' for gas management means you should turn back when you have used how much of your starting gas supply?

Answer: One third

The rule of thirds reserves one third for the exit, one third for a buddy's emergency, and one third is never used.

Which type of wreck penetration is considered the most hazardous due to reduced natural light and increased entanglement risk?

Answer: Penetration beyond the light zone

Penetrating beyond the light zone removes the diver's ability to see exits without artificial light and dramatically increases risk.

What is the primary purpose of laying a continuous guideline during cave diving?

Answer: To provide a tactile reference back to the exit in zero visibility

A continuous guideline allows divers to navigate back to the exit by feel even in zero visibility caused by silt-out.

Which certification level is required before a diver may penetrate a wreck beyond the light zone according to PADI standards?

Answer: PADI Wreck Diver Specialty

The PADI Wreck Diver Specialty teaches the skills and procedures needed for safe overhead environment penetration.

During a wreck dive, silt is disturbed and visibility drops to near zero. What is the correct immediate action?

Answer: Stop all movement, stay calm, and follow the guideline to the exit

Stopping movement prevents further silting, and following the pre-laid guideline allows a controlled exit without visibility.

What does the term 'cavern zone' refer to in cave diving?

Answer: The area within 60 meters of the entrance where natural light is visible

The cavern zone is defined as the area within 60 meters of the entrance where a diver can always see natural light.

Which equipment item is considered mandatory for safe wreck and cave penetration diving beyond the recreational cavern zone?

Answer: Redundant guideline reels

A primary and backup reel ensure a diver can re-establish a lost guideline and always maintain a continuous line to the exit.