SDI (Scuba Diving International) Part 2 Questions and Answers | Latest Update 2024/2025

What is the absolute pressure (in atmospheres/bars, ATM) at 20 meters(66 feet) ~~> 2 ATM What will be the volume in a ball that is filled with two cubic feet of air at 99 feet when it's taken to the surface? ~~> 8 cubic feet How many more times dense is the air in a balloon at 4 ATM/bar compared to the air density at the surface? ~~> 4x (4 times) If a scuba cylinder lasts 2 hours at sea level, how long will it last at 20 meters (66 feet)? ~~> 40 minutes How often should a scuba diver equalize during a descent? ~~> at the surface and every couple of feet as you descend. 2 | P a g e | © copyright 2024/2025 | Grade A+ Master01 | September, 2024/2025 | Latest update What should you do if you experience discomfort in your ears upon descending? ~~> Stop and ascend a few feet until you no longer feel any discomfort. Try to equalize again and continue with your descent. What is a reverse block? ~~> When air cannot escape from a air space during ascent What should you do if you experience a reverse block upon ascending? ~~> Descend a couple of feet until the pain subsides, wait a minute, and continue your ascent. What is the most important rule in scuba diving? ~~> keep breathing and never hold your breath What is the most serious injury that a diver could suffer from if they hold their breath upon ascending? ~~> lung over-expansion injury or ruptured lung Which gas component in air causes decompression sickness and narcosis? ~~> nitrogen 3 | P a