SDI Open Water Scuba Diver Practice Exam

What is the primary cause of waves in water?

1. Volcanic activity

2. Tidal forces

3. Wind

4. Underwater earthquakes

The correct answer is: Wind

The primary cause of waves in water is wind. When wind blows across the surface of the ocean or other bodies of water, it transfers energy to the water, creating ripples that can grow into larger waves. The size and strength of these waves are influenced by factors such as wind speed, duration, and the distance over which the wind blows (known as fetch). While tidal forces and underwater earthquakes do generate waves, they are not the primary cause of the numerous and continuous waves seen on the surface of oceans. Tidal forces lead to more predictable and gradual changes in water levels, known as tides, rather than the movement typical of wave formation. Underwater earthquakes can create tsunami waves but occur much less frequently compared to the everyday waves generated by wind. Volcanic activity can also result in waves, but again, this is a rarer phenomenon. Understanding the role of wind helps clarify why it is the fundamental cause of most wave activity seen in aquatic environments.