SDI Open Water Scuba Diver Exam
2025 Questions and Answers
How does the size and distance of objects under water differ from their
appearance in air? - ANSWER-Water is denser than air, therefore both light and
sound travel differently under water than they do on the surface.
Refraction - ANSWER-A magnifying effect created as light passes from the water
through the mask lens and BENDING into the space inside.
Why are dive mask needed to be worn from a visual aspect? - ANSWER-To focus
under water, our eyes require an air space in front of them, just as they do on land.
How much closer and larger do items appear under water? - ANSWER-
Underwater, objects appear 25% closer and 1/3 larger than they do on land.
How does depth affect the appearance of colors under water? - ANSWER--As
light passes through water, the water absorbs much of its color.
-Reds are the first to disappear, followed by oranges, yellows, greens, and other
colors of the spectrum.
COPYRIGHT ©️ 2025 ALL RIGHTS RESERVED...TRUSTED & VERIFIED 1
2025 Questions and Answers
How does the size and distance of objects under water differ from their
appearance in air? - ANSWER-Water is denser than air, therefore both light and
sound travel differently under water than they do on the surface.
Refraction - ANSWER-A magnifying effect created as light passes from the water
through the mask lens and BENDING into the space inside.
Why are dive mask needed to be worn from a visual aspect? - ANSWER-To focus
under water, our eyes require an air space in front of them, just as they do on land.
How much closer and larger do items appear under water? - ANSWER-
Underwater, objects appear 25% closer and 1/3 larger than they do on land.
How does depth affect the appearance of colors under water? - ANSWER--As
light passes through water, the water absorbs much of its color.
-Reds are the first to disappear, followed by oranges, yellows, greens, and other
colors of the spectrum.
COPYRIGHT ©️ 2025 ALL RIGHTS RESERVED...TRUSTED & VERIFIED 1
