A small bronze box washes ashore. While it's an odd bit of cargo to wind up overboard, it looks perfectly innocuous, if sturdy and water tight.
Then the box drags itself further inland, and opens.
Inside is an amulet, resting comfortably on a tidal map. She's in the right area, she thinks, but sailing's hard enough even when one's vessel isn't a literal box thrown into the ocean, she's probably not quite where she intended to be just yet.