I was "buzzed" by a Coast Guard Boat in NY harbour the other day. I was within 100 yards of the Staten island ferry, which I guess was the problem. There was a guy behind the .50 machine gun in the front. They came in at high speed. Turned right between us and the ferry. Was a little scary. There is so much traffic in NY harbor it is very tough to stay away from everything.
They have been escorting the SI ferry now for a couple of years...I noticed it last year on the anniversary of 9/11 usually it's the NYPD.. though I do see the CG out too.