I often park at the Cape Cod Canal (MA) for several hours boat watching - from small sailboats to barges and today I was watching a barge pushed by a tug pass by in front of my car some 100 feet away. I always turn the V1 off but today I forgot and when the tug crossed the V1's aimed direction, the laser alert started beeping on and off every couple of seconds. When this barge passed about several degrees off-axis, the alert stopped. When the second tug passed by (a back-up tug), the same happened again. Seems these tugs are now using a laser to center the tug in the canal (deepest area) by reflections off the shoreline at night and day.

You just never know what the V1 will pick up on the sensitive laser band!