If possible.. report it to the Coast Guard.
They may locate it and mark it and have it removed if a serious hazard to naviagation.
I noticed a few weeks ago what looks like a railroad tie sticking about 6 inches out of the water. I saw that it was still in the same location yesterday. I went over to it and poked it with a pole. It moves slightly but seems to be dug into the bottom. If someone is running at any speed and hits it they are going to have a real problem.
I marked it on my GPS. The coordinates are: N 38'58.721 W76'13.093
It is not that far off Long Point. If you are cruising the Chester be mindful of it. I hit a submerged log for the first time in Eastern Bay a little over a month ago and it about knocked the fillings out of my teeth. No damage to the boat though. This thing I am talking about would bust a hull if hit just right.
I am in the Chester all the time - thaks for the heads up.