How enter a harbor and see a boy with white vertical stripes what kind of bouy is that?

The boy with white vertical stripes likely indicates a "safe water" buoy, often referred to as a fairway buoy. These buoys mark the entrance to a channel or harbor and signify that there is navigable water all around. They typically have a red and white striped pattern and are used to guide vessels safely through waterways. Always be sure to follow local navigation rules and guidelines when approaching a harbor.