SDI FINAL EXAM QUESTIONS AND
ANSWERS
1.Objects under water appear:
1: The same size as they do on
land. 2: Twice as large as they
do on land.
3: Closer and larger than they do on land.
4: Smaller and farther away than they do on land.: Closer and
larger than they do on land.
2.As you descend:
1: Colors appear to fade.
2: Reds and oranges are among the first colors to disappear.
3: At 30 m/99 ft, little color remains other than blues, grays,
blacks and whites. 4: All of the above.: All of the above.
3.Which of the following statements is true? There may be
more than one correct answer.
1: Water is 400 times denser
than air. 2: Water is 800 times
denser than air.
3: Sound travels about four times faster underwater.
4: Both the second and the third answer are correct.: Both the
second and the third answer are correct.
4.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
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, SDI FINAL EXAM QUESTIONS AND
ANSWERS
salt water does. 4: Salt water conducts heat away from your
body faster than fresh water does.: Water conducts heat away from
your body 25 times faster than air does.
5.When water stratifies itself into layers, according to
temperature, the bound- ary between layers is known as a(n):
1: Halocline.
2: Ichtyocline.
3: Thermodyne.
4: Thermocline.: Thermocline.
6.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.: All of the above.
7.The sun warming water near the equator, coupled with the
earth's rotation, is the primary cause of permanent ocean
currents.
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, SDI FINAL EXAM QUESTIONS AND
ANSWERS
1: True.
2: False.: True.
8.Which of the following is/are true?
1: If caught in a rip current, swim directly towards shore, using
the most powerful kick possible.
2: If caught in a rip current, swim perpendicular to shore, until
you are com- pletely out of the rip current, then swim in towards
shore.
3: If caught in a rip current, swim parallel to shore, until you
are completely out of the rip current, then swim in towards
shore.
4: Don't fight the rip current; relax and let it carry you closer to
shore.: If caught in a rip current, swim parallel to shore, until you are
completely out of the rip current, then swim in towards shore.
9.We measure waves by their height
and weight. 1: True.
2: False.: False.
Explanation:
We measure waves by their height and length.
10.Which of the following best describes the formation of surf?
1: Waves energy, rebounding from its impact with shore,
crashes into oncom- ing waves, causing them to break.
2: Entering shallow water forces wave energy upward, making
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, SDI FINAL EXAM QUESTIONS AND
ANSWERS
the wave crest unstable and causing it to break.
3: A wave encountering shallow water begins to slow at its
bottom, while the top of the wave continues at its previous
speed. This causes the wave to break. 4: As waves enter shallow
water, the distance between wave crests (wave length)
shortens, increasing the tendency to break.: Only the third answer
(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) is correct.
11.Surge:
1: Occurs when waves force water between facing rock ledges.
2: Is the back-and-forth movement of water caused by waves
passing over head.
3: Is the backwash of water from waves breaking on shore.
4: None of the above.: Surge is the back-and-forth movement of
water caused by waves passing over head.
12.Which 'if any' of the following are true?
1: Aquatic animals present a greater risk to divers than any
other factor.
2: Most aquatic animal bites result from an animal's defensive
response to a
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ANSWERS
1.Objects under water appear:
1: The same size as they do on
land. 2: Twice as large as they
do on land.
3: Closer and larger than they do on land.
4: Smaller and farther away than they do on land.: Closer and
larger than they do on land.
2.As you descend:
1: Colors appear to fade.
2: Reds and oranges are among the first colors to disappear.
3: At 30 m/99 ft, little color remains other than blues, grays,
blacks and whites. 4: All of the above.: All of the above.
3.Which of the following statements is true? There may be
more than one correct answer.
1: Water is 400 times denser
than air. 2: Water is 800 times
denser than air.
3: Sound travels about four times faster underwater.
4: Both the second and the third answer are correct.: Both the
second and the third answer are correct.
4.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
1/
31
, SDI FINAL EXAM QUESTIONS AND
ANSWERS
salt water does. 4: Salt water conducts heat away from your
body faster than fresh water does.: Water conducts heat away from
your body 25 times faster than air does.
5.When water stratifies itself into layers, according to
temperature, the bound- ary between layers is known as a(n):
1: Halocline.
2: Ichtyocline.
3: Thermodyne.
4: Thermocline.: Thermocline.
6.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.: All of the above.
7.The sun warming water near the equator, coupled with the
earth's rotation, is the primary cause of permanent ocean
currents.
2/
31
, SDI FINAL EXAM QUESTIONS AND
ANSWERS
1: True.
2: False.: True.
8.Which of the following is/are true?
1: If caught in a rip current, swim directly towards shore, using
the most powerful kick possible.
2: If caught in a rip current, swim perpendicular to shore, until
you are com- pletely out of the rip current, then swim in towards
shore.
3: If caught in a rip current, swim parallel to shore, until you
are completely out of the rip current, then swim in towards
shore.
4: Don't fight the rip current; relax and let it carry you closer to
shore.: If caught in a rip current, swim parallel to shore, until you are
completely out of the rip current, then swim in towards shore.
9.We measure waves by their height
and weight. 1: True.
2: False.: False.
Explanation:
We measure waves by their height and length.
10.Which of the following best describes the formation of surf?
1: Waves energy, rebounding from its impact with shore,
crashes into oncom- ing waves, causing them to break.
2: Entering shallow water forces wave energy upward, making
3/
31
, SDI FINAL EXAM QUESTIONS AND
ANSWERS
the wave crest unstable and causing it to break.
3: A wave encountering shallow water begins to slow at its
bottom, while the top of the wave continues at its previous
speed. This causes the wave to break. 4: As waves enter shallow
water, the distance between wave crests (wave length)
shortens, increasing the tendency to break.: Only the third answer
(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) is correct.
11.Surge:
1: Occurs when waves force water between facing rock ledges.
2: Is the back-and-forth movement of water caused by waves
passing over head.
3: Is the backwash of water from waves breaking on shore.
4: None of the above.: Surge is the back-and-forth movement of
water caused by waves passing over head.
12.Which 'if any' of the following are true?
1: Aquatic animals present a greater risk to divers than any
other factor.
2: Most aquatic animal bites result from an animal's defensive
response to a
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