The Coast Guard wants to ban swimmers under the Mackinac Bridge for a 'marine event'

The Coast Guard proposes a temporary safety zone around the Mackinac Bridge in Michigan. This zone would prohibit all vessels and people from a 100-yard radius around the bridge's center span.

This is a small, temporary restriction for a specific event. It shows how local authorities use their power to manage public access to waterways for safety. These kinds of temporary zones are common for events like boat races or fireworks displays.