Scuba AFS 270 SDI Midterm Exam
Questions and Answers 100% Pass
closer and larger - ✔✔objects underwater appear ___ and ___ than they do
on land
4 (none of the above) - ✔✔As you descend:
1: Colors will remain largely the same.
2: Blues and grays disappear quickly.
3: Dive lights have little effect on apparent color.
4: None of the above.
25x - ✔✔Water conducts heat away from your body ____x as fast as air
does
thermocline - ✔✔When water stratifies itself into layers, according to
temperature, the boundary between layers is known as a(n):
1
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,4 (all of the above) - ✔✔Which of the following is/are true?
1: Tides can make the water at a particular dive site noticeably deeper or
shallower than you may have experienced previously.
2: Tidal currents can be very strong, making diving difficult or even
dangerous.
3: Strong tidal currents can have an adverse effect on visibility.
4: All of the above.
2 (Water conducts heat away from your body 25 times faster than air does)
- ✔✔Which of the following is/are true?
1: Water conducts heat away from your body ten times faster than air does.
2: Water conducts heat away from your body 25 times faster than air does.
3: Fresh water conducts heat away from your body faster than salt water
does.
4: Salt water conducts heat away from your body faster than fresh water
does.
2
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,3 (Divers may require more in the way of exposure protection at depth
than they will at the surface) - ✔✔The presence of thermoclines means that:
1: Surface temperatures will provide divers with a good indication of what
they can expect at depth.
2: Divers may require less in the way of exposure protection at depth than
they will at the surface.
3: Divers may require more in the way of exposure protection at depth than
they will at the surface.
4: None of the above.
4 (both the first and second answers are correct) - ✔✔Which of the
following statements are true?
1: Wave height is the distance from its highest point (crest) to its lowest
point (trough).
2: Wave length is the distance from crest to crest.
3: Wave oscillation to calculated by multiplying the wave height times its
length.
3
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, 4: Both the first and second answers are correct.
TRUE - ✔✔TRUE OR FALSE: In general, the best time to dive is during
slack tide, the period between high and low tides.
True - ✔✔TRUE OR FALSE: The sun warming water near the equator,
coupled with the earth's rotation, is the primary cause of permanent ocean
currents.
true - ✔✔T/F
A wave encountering shallow water begins to slow at it bottom, while the
top of the wave continues at its previous speed. This causes the wave to
break.
All of the above - ✔✔Which of the following statements is/are true?
1: A rip current is a narrow flow of swiftly moving water that runs
perpendicular to shore.
2: Rip currents form when water flowing out to sea is funneled through a
narrow restriction, such as two sandbars or a break in a coral reef.
4
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Questions and Answers 100% Pass
closer and larger - ✔✔objects underwater appear ___ and ___ than they do
on land
4 (none of the above) - ✔✔As you descend:
1: Colors will remain largely the same.
2: Blues and grays disappear quickly.
3: Dive lights have little effect on apparent color.
4: None of the above.
25x - ✔✔Water conducts heat away from your body ____x as fast as air
does
thermocline - ✔✔When water stratifies itself into layers, according to
temperature, the boundary between layers is known as a(n):
1
100% Pass Guarantee Katelyn Whitman, All Rights
,4 (all of the above) - ✔✔Which of the following is/are true?
1: Tides can make the water at a particular dive site noticeably deeper or
shallower than you may have experienced previously.
2: Tidal currents can be very strong, making diving difficult or even
dangerous.
3: Strong tidal currents can have an adverse effect on visibility.
4: All of the above.
2 (Water conducts heat away from your body 25 times faster than air does)
- ✔✔Which of the following is/are true?
1: Water conducts heat away from your body ten times faster than air does.
2: Water conducts heat away from your body 25 times faster than air does.
3: Fresh water conducts heat away from your body faster than salt water
does.
4: Salt water conducts heat away from your body faster than fresh water
does.
2
100% Pass Guarantee Katelyn Whitman, All Rights
,3 (Divers may require more in the way of exposure protection at depth
than they will at the surface) - ✔✔The presence of thermoclines means that:
1: Surface temperatures will provide divers with a good indication of what
they can expect at depth.
2: Divers may require less in the way of exposure protection at depth than
they will at the surface.
3: Divers may require more in the way of exposure protection at depth than
they will at the surface.
4: None of the above.
4 (both the first and second answers are correct) - ✔✔Which of the
following statements are true?
1: Wave height is the distance from its highest point (crest) to its lowest
point (trough).
2: Wave length is the distance from crest to crest.
3: Wave oscillation to calculated by multiplying the wave height times its
length.
3
100% Pass Guarantee Katelyn Whitman, All Rights
, 4: Both the first and second answers are correct.
TRUE - ✔✔TRUE OR FALSE: In general, the best time to dive is during
slack tide, the period between high and low tides.
True - ✔✔TRUE OR FALSE: The sun warming water near the equator,
coupled with the earth's rotation, is the primary cause of permanent ocean
currents.
true - ✔✔T/F
A wave encountering shallow water begins to slow at it bottom, while the
top of the wave continues at its previous speed. This causes the wave to
break.
All of the above - ✔✔Which of the following statements is/are true?
1: A rip current is a narrow flow of swiftly moving water that runs
perpendicular to shore.
2: Rip currents form when water flowing out to sea is funneled through a
narrow restriction, such as two sandbars or a break in a coral reef.
4
100% Pass Guarantee Katelyn Whitman, All Rights
