Its VERY easy at night on the C&D to be fooled by oncoming LARGE ships because their running light are so much higher than the yellow vapor lights; and, because of the brightness of the vapor light, you wont see the running lights ... unless you continually look 'high'.I have been in the C&C Canal once at night when we saw a big ship ( lights and radar) and pulled to the side. There was a 35 ft sailboiat following us a half mile back who stayed in the center. The freighter blew his horn at 10PM right next to us and we almost jumped out of the boat.
I have seen the lights of truck and they are confusing although those yellow vapor arc lights of the canal are bright.
One good way to find/visualize such ships because of the glare is to watch for what appears to be 'missing' vapor lights, then look 'higher' for the running lights. The sodium vapor lights are continuous and regular with very few exceptions such as near the Rt 213 bridge at Chesapeake City, and the entrance to Summit North Marina ... otherwise they're quite regularly spaced.
Tow boats aren't a problem because their running lights are much closer to the water.