Conscientious, contact-free diving means diving in control at all times. You should constantly be aware of where you are in the water column. If your buoyancy is under control you won't unconsciously float up or sink — or if you do, you'll immediately recognize the situation and ...

The ability of light to pass through water (and our ability to see clearly) is also influenced by its turbidity. Turbidity is influenced by many factors but they can be grouped into two large classes, things suspended in the water and things dissolved in the water. Suspended ...

The next major change in our vision when we are diving is that the colors often seem drab. This is because water absorbs light. Colors are simply light of different wavelengths and water absorbs them at different rates so that after light has passed through about ...

The amount light is focused when it passes through the cornea is due to the difference in density between air and the cornea. The cornea has a density almost the same as water and therefore the difference in density between water and the cornea is very ...

Before each dive, work with your stu­dents to closely examine the objects of their fear, help them rationally weigh the risks, and then develop a sound procedure to control the perceived risk or danger. By teaching our students to perform such an analysis, the stresses associated with common ...