Strage lights over the river in NH

I believe this is my 2nd UFO sighting. When I was in highschool we lived in thi shousing development in Portsmouth, NH. Our house had a view of the Pisctaqua river which seperates Maine from New Hampshire. This river was known in the 50's or 60's to have numerous UFO sighting spanning over a weeks time with many coming to view the lights. This particular incident that I had witnessed was zat night and it was dark. I was in the living room talking to my friend on the phone. As I was talking on the phone I was looking out the big picture window. I saw this light in the sky. It didn't look any different than a bright star. The thing that made it stand out was the fact it bobbing up and down and sometimes left to right. I watched it for about a minute and then it went straight up and out of my sight. I tried to take a picture of it but it came out dark probaly beacause I had taken it from through the window. I really belive that it was a UFO. I have always believed in UFO's having always been told as a child the story of Betty and Barney HIll (we lived down the street from them). Both times that I believe I have seen UFO's I was not looking for them.
Date is approximate.  PD