Typically, divers use "booties" that are made of neoprene. That is the same material wetsuits are made of. They usually have rubber on the bottom of them so you don't slip around, but they are made to wear while wearing fins. You put the booties inside the fin for maximum comfort while diving. They're usually about 20-30 bucks at the dive shops and last about 5 years assuming you dive about 20 times a year.
Free divers do but scuba divers do not need to. Scuba divers take their air with them and would have no need to hyperventilate.
300 feet
about 10 metres/30 feet most of the time but deep sea divers can go to depths of about 30 metres/90 feet
The flippers help divers move at greater speeds and force and is less taxing on the diver.
they need protection from stuff
Sunlight only reaches down to 650 feet below the surface of ocean. This "sunlit zone" is where all sea plants and most sea animals live. From 3,280 feet onward, is completely dark.
They need to know how to swim away from sharks and such!
2200
It depends upon your state law, but 100 feet would be a general answer.
Hell if ik..
200 feet
Like all adults or older teenagers; scuba divers need English and Maths also physics and scuba diving training. Hope I answered your question xx