SSI Science of Diving – Comprehensive Study Guide, Key Concepts & Practice
Questions Review
If the volume of a gas is kept constant, what varies directly with temperature? - correct answer
✔✔Pressure
At an altitude of about 16,000 feet, the atmospheric pressure is approximately - correct answer
✔✔one half the atmospheric pressure at sea level
A diver and their equipment weighs 175 lbs. and is neutrally buoyant in saltwater. To be
neutrally buoyant in freshwater, diving with the same equipment, they must - correct answer
✔✔remove weight
The absolute pressure at a depth of 165 feet in salt water is - correct answer ✔✔6ata
Objects do not appear the same in the underwater environment as they do on land. Some
major factors that influence this difference in appearance are - correct answer ✔✔Refraction,
Absorption, Diffusion, and Turbidity
The partial pressure law (Dalton) requires the sum of the partial pressures to always be equal
with which pressure? - correct answer ✔✔Absolute
The greatest expansion or compression per foot happens in which depth area? - correct answer
✔✔First 33 FT
If you have difficulty equalizing pressure in your ears/sinuses while descending, you should -
correct answer ✔✔ascend until the pressure is relieved and then attempt equalization
, Which of the following statements concerning heat stroke is not true? - correct answer
✔✔Perspiration Increases
When oxygen pressure in the body drops below a ppO2 of 0.17 ata, mild symptoms of hypoxia
occur. Blackout and death may occur if the ppO2 drops to - correct answer ✔✔0.10 ata
Which of the following is not a symptom of decompression sickness? - correct answer
✔✔Cyanosis (Bluish Skin Color)
How many pairs of sinuses does a person have? - correct answer ✔✔Four
Hypothermia means a lower than normal - correct answer ✔✔body core temperature
As you dive deeper, the narcotic effect of nitrogen gets - correct answer ✔✔Greater
Hypoxic hypoxia is by far the most common form of hypoxia. This condition is - correct answer
✔✔where the partial pressure of oxygen in the arterial blood is too low
At sea level, human body tissues are saturated with nitrogen at a partial pressure equal to -
correct answer ✔✔the partial pressure of the gas in alveolar air
Multi-level dives, in general, are those where - correct answer ✔✔divers spend time at
progressively shallower depths during the dive, which allows extended bottom time
Tissue half-time is a method used to describe the time required for the amount of gas in a
particular tissue to change by - correct answer ✔✔50 Percent
Recreational divers control the desaturation process by - correct answer ✔✔executing a 30 FT
per Min ascent and making a 3-5 min safety stop at 15 FT
Questions Review
If the volume of a gas is kept constant, what varies directly with temperature? - correct answer
✔✔Pressure
At an altitude of about 16,000 feet, the atmospheric pressure is approximately - correct answer
✔✔one half the atmospheric pressure at sea level
A diver and their equipment weighs 175 lbs. and is neutrally buoyant in saltwater. To be
neutrally buoyant in freshwater, diving with the same equipment, they must - correct answer
✔✔remove weight
The absolute pressure at a depth of 165 feet in salt water is - correct answer ✔✔6ata
Objects do not appear the same in the underwater environment as they do on land. Some
major factors that influence this difference in appearance are - correct answer ✔✔Refraction,
Absorption, Diffusion, and Turbidity
The partial pressure law (Dalton) requires the sum of the partial pressures to always be equal
with which pressure? - correct answer ✔✔Absolute
The greatest expansion or compression per foot happens in which depth area? - correct answer
✔✔First 33 FT
If you have difficulty equalizing pressure in your ears/sinuses while descending, you should -
correct answer ✔✔ascend until the pressure is relieved and then attempt equalization
, Which of the following statements concerning heat stroke is not true? - correct answer
✔✔Perspiration Increases
When oxygen pressure in the body drops below a ppO2 of 0.17 ata, mild symptoms of hypoxia
occur. Blackout and death may occur if the ppO2 drops to - correct answer ✔✔0.10 ata
Which of the following is not a symptom of decompression sickness? - correct answer
✔✔Cyanosis (Bluish Skin Color)
How many pairs of sinuses does a person have? - correct answer ✔✔Four
Hypothermia means a lower than normal - correct answer ✔✔body core temperature
As you dive deeper, the narcotic effect of nitrogen gets - correct answer ✔✔Greater
Hypoxic hypoxia is by far the most common form of hypoxia. This condition is - correct answer
✔✔where the partial pressure of oxygen in the arterial blood is too low
At sea level, human body tissues are saturated with nitrogen at a partial pressure equal to -
correct answer ✔✔the partial pressure of the gas in alveolar air
Multi-level dives, in general, are those where - correct answer ✔✔divers spend time at
progressively shallower depths during the dive, which allows extended bottom time
Tissue half-time is a method used to describe the time required for the amount of gas in a
particular tissue to change by - correct answer ✔✔50 Percent
Recreational divers control the desaturation process by - correct answer ✔✔executing a 30 FT
per Min ascent and making a 3-5 min safety stop at 15 FT
