How does looking at something underwater affect its apparent size? the make them looker larger and/or closer How does water affect light intensity and color? as you go deeper, it gets darker and colors start to fade. the pressure test is done every two to five years. Why do you need scuba tank visual inspections and pressure tests and how often are they done? to keep the maintenance of the cylinder and to know it is properly working. What's the best way to keep water out of a scuba tank? to never completely empty it and store the cylinder in a standing position. with the DIN system, the regulator threads into the valve. What are two basic types of tank valves? yoke and DIN What's the difference between a DIN valve and a yoke valve? the yoke system holds the first stage to the cylinder with a clamp system.

secure the strap locking device if it has one. fit it over the crown of your head, above your ears, with a snug but not overly tightly fit. What is the most important rule in scuba diving? to breathe continuously and never, ever hold your breath What are the consequences of breaking the most important rule in scuba diving? lung overexpansion injuries How does increasing depth affect how long your air supply lasts? it shortens it What's the most efficient way to breathe dense air underwater? take slow, deep breaths When selecting scuba equipment, what are the three most important factors? suitability, fit, and comfort How do you prepare a new mask for use? you may need to scrub the interior of the glass with a mask cleaner.

Padi scuba final exam