1. Properties of Water Light Sound Temperature Density

2. Objectives Compare the properties of water to the properties of air with regard to: Light, Sound, Temperature and Density. Describe the effects of the properties of water on a diver.

3. Light Refraction –Objects appear closer and larger Absorbption –Lose colors as you descend Turbidity –Particulate matter in the water –Similar to diving in fog

4. Sound Speed –Approximately 4x faster Direction –Appears to come from above and all around Communication –Hand signals –Maintain visual contact

5. Temperature Conduction –Water conducts heat approximately 25x faster than air –Chill 25x more quickly in water than in air Capacity –By volume, water has 3200x the capacity of air to absorb heat –By mass, water has 4x the capacity of air to absorb heat Once cold it is difficult to warm up

6. Density Definition: mass to vol. –Air =.09lbs/cu ft –Sea water (sw) = 64 –Fresh water (fw) = 62.4

7. Air and Water – Density

8. Summary Anticipate how the properties of water will effect you as a diver and take action to either take advantage of those effects or to minimize any adverse effects.