A more thorough explanation:

Definition: Territorial property refers to land and water that a state has jurisdiction and control over, regardless of whether the legal title is held by the state or a private individual or entity. This includes lakes and waters that are wholly within a state, as well as the marginal sea within the three-mile limit. However, bays and gulfs may not always be recognized as state property.

Examples:

• A lake located entirely within the borders of a state is considered territorial property of that state. For example, Lake Tahoe is located in California and Nevada, but each state has jurisdiction over the portion of the lake within its borders.
• The marginal sea within the three-mile limit is also considered territorial property. For example, the United States has jurisdiction and control over the waters within three miles of its coastline.
• However, bays and gulfs may not always be recognized as state property. For example, the Gulf of Mexico is not considered territorial property of any one state, but rather is shared by several states and countries.

The examples illustrate how territorial property can vary depending on the location and type of body of water. It is important for states to have jurisdiction and control over their territorial property in order to regulate activities such as fishing, boating, and resource extraction.