21 GCA § 9202
Boundaries by Water
View official PDF ↗COL120106 CH. 9 R IGHTS OF O WNERS Except where the grant under which the land is held indicates a different intent, the owner of the upland, when it borders on tidewater, takes to ordinary high-water mark; when it borders upon a navigable stream, where there is no tide, the owner takes to the edge of the stream, at lowwater mark; when it borders upon any other water, the owner takes to the middle of the stream.
Reconstructed from the Guam Code Annotated. For the authoritative version, see the official PDF.