SDI chapter 1
What does SCUBA stand for? - answer self-contained underwater breathing apparatus
List the three important scuba diving changes that occurred in the 1950s. - answer dive
tables, pdc (personal dive computer), and enhanced diving equipment
Name three different devices that modern dive computers replace. - answer dive tables,
gauges, and j valves
What sets Scuba Diving International apart from other training agencies? – answer SDI
was the first dive training agency to provide entry-level scuba instruction that
incorporates the use of dive computers.
How much larger and closer do objects appear underwater and why? - answer33%
larger and 25% closer. This happens because a dive mask creates an artificial airspace.
As light travels through this airspace, it bends causing a magnifying effect.
How much faster does sound move through water than air and why? - answer4 times
faster. Water is about 800 times less denser than air.
What is the first color to be absorbed underwater? - answerred
When diving from shore, the best time to dive is when there is the least amount of tidal
current. ------- tide is when there is no horizontal water movement. - answerslack
If you are caught in a rip current, first swim ------- to the current to get out of it before
swimming towards shore. - answerparallel
Waves are usually caused by -------. - answerWind pushing water on the surface
Anticipate surge action to avoid contact with stationary objects. - answertrue
What types of marine life cause most diving injuries? - answerjellyfish, fire corals, and
fish that live in and around the ocean floor.
What should you do if you see a potentially dangerous animal underwater and it does
not leave the area? - answerdon't touch the animal and respect the environment
List three different reasons that it is advisable to check with your local dive center before
conducting a dive in an area you are unfamiliar with. - answerEnvironmental conditions,
understand laws, and preparing for an emergency.
What does SCUBA stand for? - answer self-contained underwater breathing apparatus
List the three important scuba diving changes that occurred in the 1950s. - answer dive
tables, pdc (personal dive computer), and enhanced diving equipment
Name three different devices that modern dive computers replace. - answer dive tables,
gauges, and j valves
What sets Scuba Diving International apart from other training agencies? – answer SDI
was the first dive training agency to provide entry-level scuba instruction that
incorporates the use of dive computers.
How much larger and closer do objects appear underwater and why? - answer33%
larger and 25% closer. This happens because a dive mask creates an artificial airspace.
As light travels through this airspace, it bends causing a magnifying effect.
How much faster does sound move through water than air and why? - answer4 times
faster. Water is about 800 times less denser than air.
What is the first color to be absorbed underwater? - answerred
When diving from shore, the best time to dive is when there is the least amount of tidal
current. ------- tide is when there is no horizontal water movement. - answerslack
If you are caught in a rip current, first swim ------- to the current to get out of it before
swimming towards shore. - answerparallel
Waves are usually caused by -------. - answerWind pushing water on the surface
Anticipate surge action to avoid contact with stationary objects. - answertrue
What types of marine life cause most diving injuries? - answerjellyfish, fire corals, and
fish that live in and around the ocean floor.
What should you do if you see a potentially dangerous animal underwater and it does
not leave the area? - answerdon't touch the animal and respect the environment
List three different reasons that it is advisable to check with your local dive center before
conducting a dive in an area you are unfamiliar with. - answerEnvironmental conditions,
understand laws, and preparing for an emergency.
