Joe wrote:
jeeze ... I try to stay out of these easy ones ... its a tow with a
blue light on the center of the lead barge.

Sorry Jeff, the blue light is not on the barge/ tow,

I thought is was a "gun sight" to help steering, not for others to see.

and you failed to
mention why a blue light is required in addition to regular towing
lights.

You didn't ask what it was for, only what it was.


Of course, it could just be the Dog Star.