Upon reaching the dive site, the most frequently asked question is “What’s the viz?” Visibility is based on how far you can see horizontally, and the visibility can range from 0 to 100 meters, or from 0 to 330 feet.
Visibility can be affected by numerous factors:
- Wind causes waves and swells that can stir up the bottom sediment.
- Currents and tides create water movement that again can stir up the bottom or bring clean or dirty water into the area.
- Rain can cause rivers to pick up more sediment and that can flow farther into the ocean.
- Bottom composition will also determine how much visibility would be affected by these factors. A fine silty bottom will stir up more easily and settle a lot slower than a coarse sand or rocky bottom.
In low visibility, stay close to your buddy or the person leading the dive (a divemaster for instance), and track your position using your compass and natural features you may be familiar with. When possible, use a reference line to descend and ascend. Or when shore diving, follow the natural navigation signs pointing to your safe entry and exit points. Your instructor will help teach you these skills, but you will gain confidence as your experience grows. Also, staying close to your buddy is always a good idea and can help prevent problems from occurring.
You should consider learning more about how to dive safely at night or in areas where the visibility is reduced. Always evaluate the conditions to determine if it is safe to dive with your current level of training and experience.