How is the boundary line of a grant of a stream whose waters are affected by the tide determined?

The boundary line of a grant of a stream whose waters are affected by the tide is determined in the same manner as other boundary lines. This means that it generally refers to the position of the water's edge, which can change due to natural conditions such as tides, erosion, and sediment deposition.

In the case of tidal waters, boundaries are typically not static and may shift over time. Therefore, the determination of boundaries in these instances relies on historically established principles that apply to all types of property lines.

While other options suggest methods like the location of mean low tide or the use of rainfall data, they do not align with how boundaries are conventionally defined. Using historical land records, while useful in some contexts, is not the primary approach taken for defining boundaries in the context of tidal waters. Instead, treatise of surveying law and historical precedence dictates the methodology used in such cases.