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Dive Decompression Terminology Practice Test

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  • What is the underlying cause of altitude sickness?
  • Left Surface is rounded in which direction?
  • In most gradient-factor based plans, what is the effect of using a higher gradient factor value?
  • Stage Depth refers to which reading?
  • Which abbreviation indicates the total decompression time during ascent?
  • TBT stands for which term?
  • If you are symptomatic at greater than 5 minutes but less than 7 minutes, which procedure applies?
  • Which of the following is a clearly technical factor affecting decompression risk?
  • Oxygen decompression stops are only done at 20 or 30 FSW.
  • What is in-water decompression and when is it used?
  • Define Maximum Operating Depth (MOD) and how it's determined for a gas.
  • If RS = 5 and SI = 2, what is LS?
  • How long does it take for equilibration to occur?
  • Which statement best describes the difference between RGBM and fixed-M decompression models?
  • What time must be added to the Bottom Time of a repetitive dive to compensate for residual nitrogen in tissues?
  • Which action is described as part of travel-rate management during ascent?
  • Which stop is a non-mandatory ascent pause intended to limit nitrogen loading?
  • What does VPM stand for and how does it differ conceptually from gradient-based models?
  • What is the last water stop depth for all decompression stops?
  • NDL stands for what in decompression terminology?
  • R stands for which term?
  • Is a delay of up to 1 minute reaching the first decompression stop ignorable?
  • Differentiate between a Deep Stop and a Decompression Stop.
  • What is CNS Oxygen Toxicity and how is it detected or prevented?
  • Oxygen decompression stops, at which depths are they specified in the material?
  • What table would you go to with Type II DCS?
  • Which statement correctly compares equilibration and acclimatization times?
  • Which of the following is NOT a non-technical factor influencing decompression risk?
  • What does spare gas refer to and how is it used in deco planning?
  • Which of the following is NOT one of the five decompression tables?
  • Decompression stops deeper than 30 FSW are performed on which breathing gas?
  • What is the FSW correction for dives between 201 and 300 feet of seawater on a zeroed gauge?
  • If RS = 7 and SI = 5, what is LS?
  • Altitude correction and its effect on no-decompression limits (NDL) is that it:
  • What is a Decompression Stop and when is it required?
  • How many different decompression tables are listed?
  • LB stands for which term?
  • Which statement about altitude sickness symptoms is correct?
  • Dive tables become less accurate as depth and time increase.
  • What is a Dive Computer and how does it differ from dive tables for decompression planning?
  • Which table is used for Surface Decompression using Oxygen (Sur D 02)?
  • True or False: 'Omitted D' may or may not be planned.
  • Which statement best describes CNS oxygen toxicity planning?
  • In asymptomatic divers longer than 7 minutes, how is the choice between Table 5 and Table 6 determined?
  • What does Acclimation refer to?
  • What term describes any dive conducted after all residual nitrogen from prior dives has been eliminated from tissues?
  • What is Enriched Air Nitrox (EANx) and why might divers choose it?
  • Decompression Table is best described as which of the following?
  • Which table is used for Surface Decompression using Air (Sur D Air)?
  • How does elevated PPO2 relate to Oxygen Toxicity risk, and what factors influence it?
  • When rounding Reach Surface, the measurement is rounded in which direction?
  • Which term refers to a scheduled ascent stop to allow nitrogen off-gassing?
  • Define Surface Interval and describe its impact on subsequent dives.
  • What are Gradient Factors in decompression theory and what do high/low values represent?
  • Who is known as the Father of Altitude Diving?
  • SI stands for which term?
  • Which abbreviation denotes the total bottom time spent in a dive?
  • What is a Gas Switch Strategy and why is it important for managing PPO2 and nitrogen loading?
  • Which statement best differentiates Descent Time from Bottom Time?
  • No Decompression Limit defines which of the following?
  • Which of the following correctly lists all four depth gauges?
  • What does Equivalent Single Dive Time represent?
  • Decompression Table is defined as which of the following?
  • Which statement accurately defines Exceptional Exposure Dive?
  • Which abbreviation corresponds to Reached Bottom?
  • Under what condition is a decompression obligation added to a dive plan?
  • TBT = BT + RNT. If BT = 6 and RNT = 4, what is TBT?
  • Which statement describes Equivalent Single Dive?
  • What is the deco ceiling used to identify in some decompression models?
  • Which abbreviation is used for residual nitrogen time in planning?
  • What is Gas Switching and when might it be used during a dive?
  • When is a Safety Stop typically performed and what are its characteristics?
  • If you arrive early at a decompression stop, when should you begin timing the first stop?
  • What designation is used to indicate the amount of nitrogen remaining in a diver's body after a previous dive?
  • What are Type I and Type II decompression sickness symptoms and how do they differ?
  • How do MOD and NDL interact when planning a nitrox-based decompression schedule?
  • What is a primary decompression risk of rapid ascent?
  • If you are asymptomatic at greater than 7 minutes and you have 2 or fewer Sur D02, which table is used?
  • Which term measures the overall duration from leaving the surface at the start until returning to the surface after the dive?
  • Which unit is used to express decompression stop depths in the material?
  • The ascent rate from the last water stop to the surface for Sur D 02 is 40 fpm.
  • What is the formula to find the Altitude Stop Depth using Cross Corrections?
  • Which statement best describes the hazards of an Exceptional Exposure Dive?
  • What does LS stand for in diving terminology?
  • L stands for which term?
  • PPO2 at surface breathing air (21% O2) is which value?
  • How does surface interval credit affect repetitive dive planning with air tables?
  • What does gradient factor primarily influence in decompression planning?
  • Stage Depth is defined as which of the following?
  • What best defines a Decompression Schedule?
  • If you are symptomatic at 5 minutes or less, which procedure is indicated?
  • What table would you go to with Type I DCS?
  • Which abbreviation represents the time between surfacing and the next dive?
  • Explain Equivalent Air Depth (EAD) and its use in nitrox planning.
  • What is a no-fly time and why is it recommended after a dive?
  • TDT stands for which term?
  • How much time do you have to enter the chamber after surfacing?
  • How is altitude diving different in terms of decompression planning?
  • If LB = 25 and LS = 12, what is BT?
  • Is it safe to dive at altitude with pulmonary edema?
  • What is RGBM decompression and how does it differ from traditional models?
  • What is Surface Decompression?
  • The time 2400 or 0000 corresponds to which moment?
  • What is the standard format for representing Surface Interval?
  • True or False: No correction is needed on FSW for dives between sea level and 300 fsw.
  • What does equilibration refer to?
  • What are common PPO2 safety limits used in recreational planning and why?
  • If you are asymptomatic at greater than 5 minutes but less than 7 minutes, which procedure is indicated?
  • Which depth range requires a +7 FSW correction on a zeroed gauge?
  • What term defines any dive conducted while residual nitrogen remains from a prior dive?
  • Hyperbaric Oxygen Therapy (HBOT) is a high-pressure treatment using 100% oxygen. When is it indicated?
  • What term refers to the nitrogen gas still dissolved in a diver's tissues after surfacing?
  • Descent Time is defined as which of the following?
  • Which factor primarily determines the deepest safe depth for a nitrox dive?
  • Explain CNS Oxygen Toxicity Threshold and how it's used in planning.
  • Which table provides limits when no decompression is required?
  • What describes a dive that requires decompression stops during ascent?
  • Maximum Depth is defined as which of the following?
  • Why might a diver perform a Safety Stop at 5 meters instead of 3 meters?
  • After CNS Oxygen Toxicity symptoms have subsided, when should oxygen breathing be resumed?
  • For a No-D diver who ascends faster than 30 FSW/Min and is asymptomatic and does not need recompression, how long should you observe on the surface?
  • What is a Bühlmann decompression model and what is its key characteristic?
  • In multi-gas decompression, how does a dive computer adjust when PPO2 limits are reached?
  • How is depth adjusted when using a non-zeroed gauge at altitude?
  • How does PPO2 change with depth when breathing a fixed oxygen fraction?
  • Which device computes No-Decompression Limits and decompression stops in real time?
  • Which term refers to the designation indicating the nitrogen load after a prior dive?
  • The 4 ways to treat for Pulmonary Edema: which is the initial step?
  • Describe the difference between an 'air dive' plan and a 'nitrox plan' in terms of NDL and PPO2.
  • What does NDL credit refer to in surface interval planning for repetitive dives?
  • If you are asymptomatic at 5 minutes or less, which procedures apply?
  • Which factor determines whether Table 5 or Table 6 is used for asymptomatic dives longer than 7 minutes?
  • FSW stands for what?
  • In decompression theory, tissue loading is best described as?
  • What is the FSW correction for dives between 301 and 400 feet of seawater on a zeroed gauge?
  • Which are three symptoms of altitude sickness?
  • If altitude-related edema is suspected, should you attempt to dive at altitude?
  • Which statement correctly describes the role of sea level pressure and altitude pressure in the TOD formula?
  • Which term is synonymous with off-gassing during ascent and serves as a stop?
  • Which breathing gas is used for decompression stops deeper than 30 FSW?
  • What does an 'air-to-nitrox switch' entail and at what depth might it occur?
  • What best describes a Deep Stop in ascent planning?
  • Which factor primarily determines the maximum operating depth (MOD) for a nitrox dive?
  • Hyperbaric Oxygen Therapy (HBOT) is indicated for which of the following conditions?
  • Which gauge uses the following stepped corrections: 0-100 fsw = +1 fsw; 101-200 fsw = +2 fsw; 201-300 fsw = +4fsw; 301-400 fsw = +7fsw?
  • Surface Decompression is described as which of the following?
  • Why is it necessary to adjust decompression tables for altitude?
  • Maximum Depth refers to which of the following?
  • Define 'ascent rate' and its typical recommended limit for safe ascent.
  • Which statement best describes a Decompression Schedule?
  • What is 'O2 exposure' and how is it tracked during a gas-switch sequence?
  • Name two non-technical factors that can influence decompression risk beyond depth and time.
  • BT = LB - LS. If LB = 20 and LS = 7, BT equals?
  • No Decompression Limit is defined as which of the following?
  • Which moment is commonly referred to as Midnight in 24-hour time notation?
  • What is Residual Nitrogen Time (RNT) and how does it affect subsequent bottom times?
  • What is Residual Nitrogen Time (RNT) and how does it affect planning?
  • What phrase denotes the deepest depth reached by any part of the diver?
  • What does alkalosis refer to?
  • Bottom Time is defined as which of the following?
  • Which term best defines residual nitrogen as the nitrogen gas still dissolved in tissues after surfacing?
  • What is the deco ceiling used to identify in some decompression models?
  • What describes a dive that does not require decompression stops during ascent?
  • In decompression theory, when are decompression stops triggered?
  • What is the formula for finding Theoretical Ocean Depth TOD using Cross Corrections?
  • What is the corrected FSW for the 301-400 fsw range on a zeroed gauge?
  • What is the purpose of a 'deco ceiling' in some models?
  • Which table is the U.S. Navy Standard Air Table?
  • What does RGBM stand for and what is its fundamental approach?
  • What is a tissue compartment in decompression models and what does it represent?
  • What is the immediate action if a diver experiences CNS Oxygen Toxicity without convulsions in the chamber?
  • In VPM, the model focuses on which factors rather than fixed M-values?
  • RNT stands for which term?
  • Which abbreviation denotes that the diver has reached a decompression stop?
  • How is a repetitive dive credit earned and used?
  • What term describes a specific decompression procedure corresponding to a defined depth and bottom time as listed in a decompression table?
  • What is no-decompression time (no-deco time) defined as in dive planning?
  • Which is NOT a listed treatment for pulmonary edema?
  • Which statement best describes equivalent narcotic depth (END)?
  • Which term represents the deepest depth attained during a dive?
  • What is the FSW correction for dives between 101 and 200 feet of seawater on a zeroed gauge?
  • Which option is NOT a listed action for CNS Oxygen Toxicity without convulsions?
  • In the TOD calculation, which term is in the numerator?
  • What is the Oxygen Window in decompression planning?
  • Altitude corrections in decompression planning are applied to which components?
  • Total Decompression Time is defined as which of the following?
  • RS stands for which term?
  • In nitrox planning, what does MOD constraints refer to?
  • What does No-Decompression Limit (NDL) mean in dive planning?
  • Explain Equivalent Narcotic Depth (END) and its role in nitrox planning.
  • Which depth gauge type is acceptable only if properly zeroed?
  • What is an M-Value in decompression theory?
  • What does Surface Interval refer to?
  • What defines an Exceptional Exposure Dive?
  • Which term defines the total time from leaving the bottom to arriving on the surface?
  • Which statement best describes the effect of increasing the O2 fraction on the MOD for a fixed PPO2 limit?
  • If you are asymptomatic at greater than 7 minutes and you have more than 2 Sur D02, which table is used?
  • What is the Partial Pressure of Oxygen (PPO2) and how is it calculated for a given depth and O2 fraction?
  • How do dive computers manage gas exposure when using multi-gas decompression?
  • If BT = 9 and RNT = 3, what is TBT?
  • On a zeroed gauge, what is the FSW value for 0-100 fsw?
  • How long does it take for Acclimatization to occur?
  • Exceptional Exposure Dives should ALWAYS be planned in advance by Civilian Companies.
  • When you exceed your travel rate during ascent, which action is recommended?
  • SI = LS - RS. If LS = 15 and RS = 5, SI equals?
  • Which statement about depth gauges is true?
  • Total Time Of The Dive is defined as which of the following?
  • How is the deco stop depth determined in a Bühlmann model?
  • How does a gradient factor influence the conservatism of a decompression profile?
  • Which of the following describes the two mechanisms by which equilibration occurs at altitude?
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