If you look at what it says, it says that they "laid it in the reeds by the river's bank," and that is where Pharaoh's daughter found it. Moses was not in danger on the Nile. He had just been left there, and little Miriam, however old she was, was posted to watch it to see who picked it up. It does not say that it got caught in the currents of the Nile, because it probably would have ended up in the Mediterranean Sea.
They knew better. They were not dumb. They just did not throw Moses out there. They loved the kid. They put him where he could be found by somebody important. They must have known that the Pharaoh's daughter had a soft spot in her heart or something, to put it where they knew she might walk by. I am speculating a little bit here, but the way it is written here is that they put the baby where they wanted it to be found.
We all know that this was Moses. In the Kings James Bible you will find that word ark, as it is translated in the New King James, is translated as a basket. Either term is correct. An ark is a basket, but not exactly as we are going to see in just a little bit. It is the exact same Hebrew word from which Noah's ark was translated from. Moses was drawn from the waters of the Nile. The Nile had a history of frequently flooding, especially in the spring time.
