St. Johns (Route 417): a light overhead dropped to the water level and straight into the tree line.

I am veteran that has seen many night flights of helicoptors and their attack patterns, which is why I thought as this light was weaving from west to east and repeating was a helicopter. 
I started to see this light right after I had gotten onto north/east bound 417 from the Aloma on ramp.  This light peaked my interest as there was not any other cars in the immediate area.  
As i drove it was bounding back and forth in a weaving pattern over 417.  As I approached the bridge, the light went out of view.  I thought it the helicopter went out of sight, but as I looked out over the bridge, the light was almost on the water with how low it was it I couldn't take my eyes off ot it. 
Then in a flash it darted toward the north shoreline still hugging the water.  Up to this point, I still thought it to be a helicopter, but when the light kept its pace straight into the trees flickered brighter and was gone.  
As this happened I started to yell myself I didn't see this, this did not just happen, but I can't forget it.  
Thanks for being anonymous.  I needed to say something and it helps.
Witness elects to remain totally anonymous; provides no contact information.  PD