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PADI Divemaster Theory Prep

Physics, physiology, equipment and decompression theory.

Pass mark 30/40 60 minutes PADI syllabus-aligned How many can I get wrong?
Little and often beats one big session. Five minutes on the bus counts.
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Try 3 real PADI Divemaster Theory Prep questions
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Q1. At the surface, a diver is exposed to 1 atmosphere (1 bar) of pressure. What is the approximate ambient pressure at a depth of 20 metres of seawater?
  • A.  2 bar
  • B.  3 bar
  • C.  4 bar
  • D.  1.5 bar
Show answer & explanation
✓ Answer: B. 3 bar
Pressure increases by roughly 1 bar for every 10 metres of seawater, plus the 1 bar of atmospheric pressure at the surface. At 20 m that is 1 bar (surface) + 2 bar (water) = 3 bar absolute. A common mistake is forgetting to add the surface atmospheric bar.
Q2. A diver reports a mottled, itchy skin rash with a marbled appearance shortly after surfacing. What is this most likely a sign of?
  • A.  Cutaneous (skin) decompression sickness
  • B.  An allergic reaction to sunscreen
  • C.  Salt water dermatitis
  • D.  Normal skin cooling after a dive
Show answer & explanation
✓ Answer: A. Cutaneous (skin) decompression sickness
Cutaneous DCS presents as itching, a mottled or marbled rash (sometimes called 'cutis marmorata'), and can indicate bubble formation in or under the skin. While it is technically Type I DCS, it can sometimes signal more serious bubble activity elsewhere and should always be evaluated by a diving physician, not dismissed as a skin irritation.
Q3. A diver plans a repetitive dive but the RNT for that depth already meets or exceeds the no-decompression limit. What does this mean for the dive as planned?
  • A.  The dive can proceed but a decompression stop is mandatory
  • B.  The diver must select a shallower depth or extend the surface interval before diving that depth
  • C.  The dive can proceed with no changes since the RDP always allows repetitive dives
  • D.  The diver should switch to nitrox to avoid the restriction
Show answer & explanation
✓ Answer: B. The diver must select a shallower depth or extend the surface interval before diving that depth
If RNT equals or exceeds the no-decompression limit for the intended depth, the adjusted no-decompression limit is effectively zero or negative, meaning that depth cannot be dived within no-decompression limits yet. The diver must either wait longer on the surface or choose a shallower repetitive dive.
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Dive physics — pressure, buoyancy, gases · 38
Physiology & decompression sickness · 38
The RDP & dive planning · 37
Equipment & maintenance · 35
Supervision, risk & rescue basics · 36
The aquatic environment · 45
PADI Divemaster Theory Prep — common questions
Frequently asked
How many questions are in the PADI Divemaster Theory Prep?
The exam has 40 questions. Every Revision Robin mock uses the same 40-question format so your practice matches the real thing.
What is the pass mark for the PADI Divemaster Theory Prep?
You need 30 out of 40 correct to pass, which is about 75%. Our mocks mark you against this exact threshold.
How long do you get?
The test is timed at 60 minutes. Our full mock runs on the same clock so you can practise your pacing.
Are these the real exam questions?
No. Our questions are original and written to match the current syllabus, so they give realistic practice without copying the official paper. Every answer comes with a plain-English explanation. Always confirm current rules and content with PADI syllabus-aligned.