Dom,

You are correct. The state never had the authority to deed land below the OHWM on a navigable river. They may have deeded the property that way, butg they had no authority to do it in the first place.

Of course, if the sheriff doesn't see it that way, and you get thrown in the pokey, then it's going to cost you to defend yourself. It may or may not be worth it to you to test the waters, so to speak.