The "verified" navigable list is Allegheny River, Monongahela River, Youghiogheny River, Ohio River, Susquehanna River (including north and west branches), Juniata River, Little Juniata River, Schuylkill River, Lehigh River, and Delaware River.
That's "verified", meaning no question about it. There's another 100+ streams that the DCNR lists as navigable, including some notables such as Penns Creek, Elk Creek, Spring Creek, Fishing Creek, etc. But the DCNR list is based on ancient state declarations of those waterways as public highways. Since navigability is a federal thing, those declarations carry no legal weight. However, they were typically made out of need, to protect an existing navigation route from some private threat. Capability of commercial navigation is the test under federal law, and hence a history of commercial navigation is proof of that capability. The state declarations can be and have been used as evidence of that history. But it doesn't end up on the "verified" list until it's tested in court and a judge agrees.
In most of these cases the deed may show a landowner owning the streambed. But if there's a history of navigation, its federally navigable, and federal law predates the deed and grants the public rights. Thus the deed was made in error and the unlawful parts are void. So for all these streams, the answer currently is "maybe it is, maybe it isn't", but somebody needs to trespass, get taken to court, and choose to fight it in court on grounds of navigability in order to find out who's right and who's wrong. The DCNR list could be regarded as a list where, if you did go to court, you'd have some evidence to show and thus be more likely to win.
This stuff about "King's grants" are in a few select cases where the deed to the property was granted by the King of England prior to the Declaration of Independence. Hence, despite legally meeting requirements for navigability, the deed predates the federal navigability law and thus trumps it.
As for the law, the above is right:
If navigable: Streambed is public property up to the ordinary high water mark.
If not navigable: The streambed is private. If the landowner posts, you can float through, but not touch bottom, or fish. In the event that the stream itself is listed as the property line on the deed, the landowner's property extends to the middle of the stream.