Along the Potomac river the night before the Lower Potomac Marathon, I went for a walk by the Piney Point Lighthouse. It was pretty chilly and windy by the river. Inland a bit (or in protected area's), it was pretty warm, but near the water was very cold.
After the race I went back to the Piney Point Lighthouse. Near this lighthouse, there is a small walking path, a small pier and the lighthouse (first lighthouse on the Potomac River), which you can see in a few pictures.