boojum
Ignoble Miscreant
There is an anomaly in this photo. On the lower right under the blue-hulled boat. It looks like an "echo" of the yard light. This lens has a B&W UV/IR cut filter on it. What is the cause? What is the cure?
Do you mean the four blue dots under the bow?
Well, they are about diametrically across the frame from the lights (lower right/upper left) so they could very well a ghost image caused by a reflection within the lens. Maybe a reflection from a shiny metal surface (filter ring?) or within the glass itself. Best I can do!