The stage of the regulator which reduces tank pressure is: - ✔✔ first
Two types of materials that scuba tanks are made from are steel and - ✔✔ Aluminum
The _________ line is the direction of travel line on the compass. - ✔✔ Lubber
The dive knife is used primarily as a _________ for digging, cutting, pounding, and prying. -
✔✔ Tool
Markings on scuba tanks include: - ✔✔ Date of hydrostatic test, serial number, type of material
Atmospheric pressure at sea level is: - ✔✔ 14.7 pounds per square inch/1.0 atmosphere absolute
(1.01 bar)
A sealed balloon filled with air that has a volume of 4 liters at 99 feet of seawater (30.2 m) will
have a volume of _______ liters at 33 feet of seawater (10.1 m). - ✔✔ 8
The weight of freshwater is: - ✔✔ 62.4 pounds per cubic foot (1000kg/m3) (multiply psi by 144)
Air, the gas most commonly used by recreational scuba divers, is composed of: - ✔✔ 78%
nitrogen, 21% oxygen, trace gasses
, Which of the following causes objects to appear larger and closer when looking through a mask
during a dive? - ✔✔ Refraction
Sound travels approximately how many times faster in water than in air? - ✔✔ 4
A diver's body heat is lost through conduction (primarily) at a rate of approximately ______
times more rapidly than in air. - ✔✔ 25
Which of the following is an essential feature to consider when selecting a dive mask? - ✔✔
Tempered or safety glass
Snorkels over 15 inches (38 cm) in length are not recommended primarily because: - ✔✔ They
have too much dead air space
When buying or renting equipment for diving, the most important consideration is: - ✔✔ Its fit
on your body
When rinsing a regulator it is best to: - ✔✔ Leave the regulator attached to the tank or have the
dust cap in place
Three features that are common to all buoyancy control devices are: - ✔✔ An overpressure relief
valve, inflation/deflation hose, low pressure inflator hose
Three types of alternate air sources that are in common use today are: - ✔✔ Octopus rigs,
completely redundant systems, an integrated regulator into the BCD inflation/deflation hose