Diving and Snorkeling
If people are diving or snorkeling in the same waters where you are boating, you and your lookout need to watch for them and give them plenty of space.
Some states require divers to put out a special divers' flag when they are snorkeling or diving. The blue and white flag on this boat is a type of divers' flag called an alpha flag. The red and white flag in the water is a diver-down flag. The distance required between moving boats and boats flying the alpha or diver-down flag can range from 100 feet to 300 feet, depending on the state. When you are driving near boats with these flags, also watch the water for bubbles breaking the surface because those might be from divers who are farther from their boat than expected.
Check state laws where you will be boating for specific laws for diving and snorkeling (see Chapter 7).