ADCI Surface Supplied Mixed Gas Diver
Certification | 250 Practice Exam Questions,
Answers & rationales | Latest Update
EXAM QUICK REFERENCE
Section Questions Core Topics
ADCI Standards & ADCI consensus standards, OSHA, certification
1–15
Certification requirements
Gas laws, partial pressures,
Diving Physics 16–40
Boyle/Dalton/Henry/Charles/Gay-Lussac
Mixed Gas Physiology & O₂ toxicity, narcosis, DCS types, HPNS, AGE,
41–62
Medical decompression
Surface Supplied
63–80 Umbilicals, helmets, bailout, gas panels, analyzers
Equipment
Decompression Theory & US Navy tables, treatment tables, stop procedures,
81–100
Tables TT5/6/6A/4/7
Operations & Emergency Supervisor duties, team requirements, emergencies,
101–120
Response communications
Gas Mixtures, Mixing &
121–143 HeO₂, trimix, MOD, analysis, hypoxic mixes
Analysis
Heliox Procedures 131–145 Gas switches, hot water suits, commercial protocols
Supervision & Record keeping, OSHA requirements, dive plans, safety
144–155
Documentation management
Comprehensive Review 156–250 Calculations, scenarios, integration of all topic areas
SECTION 1: ADCI STANDARDS, REGULATIONS &
CERTIFICATION (Q1–30)
,1. The ADCI International Consensus Standards for Commercial Diving and Underwater
Operations are cited as the authoritative source for best practices by which U.S. government
agencies?
A) EPA, CDC, and FEMA B) OSHA, the U.S. Coast Guard, and the U.S. Army Corps of
Engineers ✅ (correct answer) C) NIOSH, FEMA, and the Department of Defense D) The
Department of Labor and the Department of Transportation only
Rationale: The ADCI Consensus Standards are specifically cited by OSHA, the U.S. Coast
Guard, and the U.S. Army Corps of Engineers as the authoritative document for best
practices in commercial diving. Compliance with ADCI standards is effectively considered
compliance with federal diving regulations for member companies.
2. To qualify for the ADCI Mixed-Gas Diver certification card, an applicant must have a
minimum of how many logged working dives?
A) 25 Air dives and 5 Mixed-Gas dives B) 50 Air dives and 10 Mixed-Gas HeO2 dives ✅
(correct answer) C) 100 Air dives and 25 Mixed-Gas dives D) 50 Air dives and 25 Mixed-Gas
dives
Rationale: ADCI requires documented proof of 50 Air working dives and 10 Mixed-Gas
HeO2 dives, plus at least 100 Air and 50 Mixed-Gas field days. These dives must be signed
off by a supervisor and performed within a 24-month period immediately prior to
certification.
3. The minimum hours of formal instruction required for commercial diver training to qualify for
ADCI certification is:
A) 300 hours B) 500 hours C) 625 hours ✅ (correct answer) D) 800 hours
Rationale: ADCI requires that commercial diver training consist of at least 625
documented hours of formal instruction in subjects set forth in the ANSI/ACDE-01-2015
standard. This minimum ensures comprehensive training in diving physics, physiology,
equipment, procedures, and safety.
4. ADCI certification cards (except entry-level tender/diver) are valid for a period of:
A) 1 year B) 2 years C) 3 years D) 5 years ✅ (correct answer)
,Rationale: ADCI certification cards for qualified divers, supervisors, and life-support
technicians are valid for 5 years from the date of issue. Entry-level tender/diver cards are
an exception. All dives required for certification must have been performed within a 24-
month period prior to issuance.
5. Which of the following recreational diving certifications is recognized by ADCI as adequate
for commercial diving activities?
A) PADI Advanced Open Water Diver B) NAUI Master Diver C) CMAS 3-star Diver D) None
of the above — recreational certifications are not recognized ✅ (correct answer)
Rationale: ADCI explicitly does not recognize PADI, NAUI, YMCA, CMAS, POSSI, or any
other recreational scuba certification for commercial diving. These are designed for
recreational activities and do not meet OSHA 29 CFR 1910.401 or 46 CFR requirements
for commercial diving operations.
6. Under ADCI standards, a mixed-gas diving medical examination must be performed by:
A) Any licensed physician, physician assistant, or nurse practitioner B) Only a licensed
physician qualified to perform commercial diver medical examinations ✅ (correct answer) C)
A certified EMT-Basic with diving experience D) The dive supervisor, if the diver has a current
recreational dive medical
Rationale: ADCI medical standards require that all diving medical examinations be
performed only by licensed physicians qualified in commercial diver medical examinations.
Physician assistants and nurse practitioners are not recognized by ADCI as qualified to
perform these examinations.
7. Under ADCI consensus standards, periodic medical examinations for divers are recommended
on what basis?
A) Every 5 years B) Every 2 years C) Annually ✅ (correct answer) D) Only after an incident
or injury
Rationale: ADCI recommends annual periodic medical examinations for all divers and
persons subjected to hyperbaric conditions. More frequent or comprehensive examinations
are required following any incident, illness, injury, surgical procedure, or hospitalization
that may affect diving fitness.
, 8. Under ADCI standards, the designation "skill levels" for diving personnel incorporates which
three primary elements?
A) Age, physical fitness, and years of experience B) Knowledge, skills/proficiency, and physical
qualifications ✅ (correct answer) C) Certification level, depth rating, and equipment
familiarity D) Training hours, logged dives, and employer recommendation
Rationale: ADCI Consensus Standards define skill levels through three elements: (1)
knowledge gained through formal training and experience; (2) skills/proficiency in tools,
equipment, and procedures; and (3) physical qualifications meeting medical requirements.
All three must be met for each assigned task.
9. The primary U.S. federal regulation that governs commercial diving operations in general
industry is:
A) 46 CFR Part 197 B) 29 CFR 1910.401–440 ✅ (correct answer) C) 33 CFR Part 147 D) 49
CFR Part 195
Rationale: OSHA's 29 CFR 1910.401–440 (Subpart T — Commercial Diving Operations) is
the primary federal standard governing commercial diving in general industry. 46 CFR
Part 197 governs commercial diving on vessels under U.S. Coast Guard jurisdiction.
Mixed-gas divers must be familiar with both.
10. A diver who experiences Type I decompression sickness that resolves completely with a
single recompression treatment:
A) Must be immediately retired from all diving activities B) Must wait a minimum of 90 days
before returning to diving C) Does not need to see a diving medical examiner before returning to
diving ✅ (correct answer) D) Requires a complete neurological evaluation before any future
dive
Rationale: Per ADCI standards, divers experiencing Type I DCS
(musculoskeletal/lymphatic symptoms only) that is fully resolved with a single treatment
table do not require a diving medical examiner's clearance before returning to diving. Type
II (neurological) or AGE cases require physician evaluation.
11. Under ADCI standards, a diver who experiences arterial gas embolism (AGE) must:
A) Be allowed to return to diving after a 24-hour surface interval B) Be evaluated by a diving
medical examiner before returning to any diving duties ✅ (correct answer) C) Automatically
Certification | 250 Practice Exam Questions,
Answers & rationales | Latest Update
EXAM QUICK REFERENCE
Section Questions Core Topics
ADCI Standards & ADCI consensus standards, OSHA, certification
1–15
Certification requirements
Gas laws, partial pressures,
Diving Physics 16–40
Boyle/Dalton/Henry/Charles/Gay-Lussac
Mixed Gas Physiology & O₂ toxicity, narcosis, DCS types, HPNS, AGE,
41–62
Medical decompression
Surface Supplied
63–80 Umbilicals, helmets, bailout, gas panels, analyzers
Equipment
Decompression Theory & US Navy tables, treatment tables, stop procedures,
81–100
Tables TT5/6/6A/4/7
Operations & Emergency Supervisor duties, team requirements, emergencies,
101–120
Response communications
Gas Mixtures, Mixing &
121–143 HeO₂, trimix, MOD, analysis, hypoxic mixes
Analysis
Heliox Procedures 131–145 Gas switches, hot water suits, commercial protocols
Supervision & Record keeping, OSHA requirements, dive plans, safety
144–155
Documentation management
Comprehensive Review 156–250 Calculations, scenarios, integration of all topic areas
SECTION 1: ADCI STANDARDS, REGULATIONS &
CERTIFICATION (Q1–30)
,1. The ADCI International Consensus Standards for Commercial Diving and Underwater
Operations are cited as the authoritative source for best practices by which U.S. government
agencies?
A) EPA, CDC, and FEMA B) OSHA, the U.S. Coast Guard, and the U.S. Army Corps of
Engineers ✅ (correct answer) C) NIOSH, FEMA, and the Department of Defense D) The
Department of Labor and the Department of Transportation only
Rationale: The ADCI Consensus Standards are specifically cited by OSHA, the U.S. Coast
Guard, and the U.S. Army Corps of Engineers as the authoritative document for best
practices in commercial diving. Compliance with ADCI standards is effectively considered
compliance with federal diving regulations for member companies.
2. To qualify for the ADCI Mixed-Gas Diver certification card, an applicant must have a
minimum of how many logged working dives?
A) 25 Air dives and 5 Mixed-Gas dives B) 50 Air dives and 10 Mixed-Gas HeO2 dives ✅
(correct answer) C) 100 Air dives and 25 Mixed-Gas dives D) 50 Air dives and 25 Mixed-Gas
dives
Rationale: ADCI requires documented proof of 50 Air working dives and 10 Mixed-Gas
HeO2 dives, plus at least 100 Air and 50 Mixed-Gas field days. These dives must be signed
off by a supervisor and performed within a 24-month period immediately prior to
certification.
3. The minimum hours of formal instruction required for commercial diver training to qualify for
ADCI certification is:
A) 300 hours B) 500 hours C) 625 hours ✅ (correct answer) D) 800 hours
Rationale: ADCI requires that commercial diver training consist of at least 625
documented hours of formal instruction in subjects set forth in the ANSI/ACDE-01-2015
standard. This minimum ensures comprehensive training in diving physics, physiology,
equipment, procedures, and safety.
4. ADCI certification cards (except entry-level tender/diver) are valid for a period of:
A) 1 year B) 2 years C) 3 years D) 5 years ✅ (correct answer)
,Rationale: ADCI certification cards for qualified divers, supervisors, and life-support
technicians are valid for 5 years from the date of issue. Entry-level tender/diver cards are
an exception. All dives required for certification must have been performed within a 24-
month period prior to issuance.
5. Which of the following recreational diving certifications is recognized by ADCI as adequate
for commercial diving activities?
A) PADI Advanced Open Water Diver B) NAUI Master Diver C) CMAS 3-star Diver D) None
of the above — recreational certifications are not recognized ✅ (correct answer)
Rationale: ADCI explicitly does not recognize PADI, NAUI, YMCA, CMAS, POSSI, or any
other recreational scuba certification for commercial diving. These are designed for
recreational activities and do not meet OSHA 29 CFR 1910.401 or 46 CFR requirements
for commercial diving operations.
6. Under ADCI standards, a mixed-gas diving medical examination must be performed by:
A) Any licensed physician, physician assistant, or nurse practitioner B) Only a licensed
physician qualified to perform commercial diver medical examinations ✅ (correct answer) C)
A certified EMT-Basic with diving experience D) The dive supervisor, if the diver has a current
recreational dive medical
Rationale: ADCI medical standards require that all diving medical examinations be
performed only by licensed physicians qualified in commercial diver medical examinations.
Physician assistants and nurse practitioners are not recognized by ADCI as qualified to
perform these examinations.
7. Under ADCI consensus standards, periodic medical examinations for divers are recommended
on what basis?
A) Every 5 years B) Every 2 years C) Annually ✅ (correct answer) D) Only after an incident
or injury
Rationale: ADCI recommends annual periodic medical examinations for all divers and
persons subjected to hyperbaric conditions. More frequent or comprehensive examinations
are required following any incident, illness, injury, surgical procedure, or hospitalization
that may affect diving fitness.
, 8. Under ADCI standards, the designation "skill levels" for diving personnel incorporates which
three primary elements?
A) Age, physical fitness, and years of experience B) Knowledge, skills/proficiency, and physical
qualifications ✅ (correct answer) C) Certification level, depth rating, and equipment
familiarity D) Training hours, logged dives, and employer recommendation
Rationale: ADCI Consensus Standards define skill levels through three elements: (1)
knowledge gained through formal training and experience; (2) skills/proficiency in tools,
equipment, and procedures; and (3) physical qualifications meeting medical requirements.
All three must be met for each assigned task.
9. The primary U.S. federal regulation that governs commercial diving operations in general
industry is:
A) 46 CFR Part 197 B) 29 CFR 1910.401–440 ✅ (correct answer) C) 33 CFR Part 147 D) 49
CFR Part 195
Rationale: OSHA's 29 CFR 1910.401–440 (Subpart T — Commercial Diving Operations) is
the primary federal standard governing commercial diving in general industry. 46 CFR
Part 197 governs commercial diving on vessels under U.S. Coast Guard jurisdiction.
Mixed-gas divers must be familiar with both.
10. A diver who experiences Type I decompression sickness that resolves completely with a
single recompression treatment:
A) Must be immediately retired from all diving activities B) Must wait a minimum of 90 days
before returning to diving C) Does not need to see a diving medical examiner before returning to
diving ✅ (correct answer) D) Requires a complete neurological evaluation before any future
dive
Rationale: Per ADCI standards, divers experiencing Type I DCS
(musculoskeletal/lymphatic symptoms only) that is fully resolved with a single treatment
table do not require a diving medical examiner's clearance before returning to diving. Type
II (neurological) or AGE cases require physician evaluation.
11. Under ADCI standards, a diver who experiences arterial gas embolism (AGE) must:
A) Be allowed to return to diving after a 24-hour surface interval B) Be evaluated by a diving
medical examiner before returning to any diving duties ✅ (correct answer) C) Automatically
