Final answer:
When operating a PWC at greater than headway speed, it is generally recommended to stay at least 100 feet away from other vessels for safety.
Step-by-step explanation:
When operating a Personal Watercraft (PWC) at greater than headway speed, it is a general safety rule to stay a minimum distance of 100 feet away from another boat or PWC. Headway speed refers to the slowest speed at which the PWC can still move and steer effectively. This distance may vary by jurisdiction, so it's important to be aware of the specific laws in your local area as they can dictate differing safety regulations regarding the operation of PWCs.