Scuba Diving Cheat Sheet 2026

The 30 highest-yield Scuba Diving facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. What does the term 'kick cycle' refer to in underwater navigation? → A unit used to estimate distance traveled underwater
2. What is a delayed surface marker buoy (DSMB)? → A marker buoy deployed underwater before surfacing
3. When conducting a buddy check, the acronym BWRAF stands for BCD, Weights, Releases, Air, and what? → Final OK
4. What should a diver do if stung by a jellyfish underwater? → Move away calmly, alert the buddy, and treat the sting after surfacing
5. A diver surfacing from a deep dive suddenly loses consciousness at the surface. The most likely cause is: → Arterial gas embolism (AGE) from lung overexpansion
6. When navigating a square pattern underwater, what degree turn is made at each corner? → 90 degrees
7. Why should the deepest dive of the day be planned first? → To minimize residual nitrogen for subsequent shallower dives
8. A diver notices their air consumption is much higher than normal at the same depth. The most likely explanation is: → Increased exertion, cold water, or anxiety elevating breathing rate
9. During a dive, a diver notices their ears feel full and painful at 15 feet. This is most likely caused by: → Failure to equalize the middle ear against increasing water pressure
10. How frequently should you visually inspect your scuba tank? → At least once a year, more frequently if used often
11. Which environmental hazard should a diver be most cautious about when diving near a coral reef? → Accidentally touching or kicking fragile coral
12. What is the role of Divers Alert Network (DAN) in relation to scuba certification? → DAN provides dive accident insurance, emergency hotline support, and safety research
13. An arterial gas embolism (AGE) is most commonly caused by which diving action? → Holding the breath while ascending
14. Dalton's Law of partial pressures states that the total pressure of a gas mixture equals: → The sum of the partial pressures of each individual gas
15. What is the primary function of a regulator in scuba diving? → Reduce tank pressure to breathable levels
16. What is the maximum depth limit for PADI Open Water certified divers? → 30 meters (100 feet)
17. Which type of fin style allows divers to wear thick booties and provides more thrust? → Open-heel fins
18. What is the typical number of open water checkout dives required for Open Water Diver certification? → 4 dives
19. True or false: I can become a safer diver and a better buddy by getting more training. → True
20. What does a diver do if they cannot equalize ear pressure during descent? → Ascend a few feet, then try equalizing again
21. What is a 'panic spiral' in scuba diving? → A sequence where anxiety leads to poor decisions, worsening the situation
22. What is the function of the second stage in a two-stage scuba regulator system? → Deliver air at ambient pressure directly to the diver's mouth
23. What is the recommended minimum safety stop depth and duration for recreational dives deeper than 60 feet (18 m)? → 15 feet (5 m) for 3 minutes
24. What does 'reciprocal recognition' mean in the scuba industry? → Certification agencies accepting each other's credentials as equivalent
25. What is 'total bottom time' (TBT) in repetitive dive planning? → Residual nitrogen time plus actual bottom time of the current dive
26. Which gas law explains why a diver's lungs could rupture if they hold their breath while ascending? → Boyle's Law
27. A diver experiences a sudden sharp pain in their ears during descent. What is the correct response? → Ascend slightly and attempt to equalize before continuing
28. When planning a drift dive, where should the diver typically exit the water? → Downstream from the entry point, at a pre-planned exit
29. What does a Divemaster certification qualify someone to do? → Lead certified divers and assist instructors
30. What is the key difference between a 'dry suit' and a 'wet suit' in terms of thermal protection? → Dry suits keep the diver's body dry by sealing out water completely