Really Cool Boats

While at a convention at the national harbor in Maryland I had the opportunity to get these pictures of some really cool boats.

Yes, that is a 50 cal mounted on the right side of it. It looks as though it is a remote control system.

Again, look at the top of this one, it has a 50 cal on it.

These really caught my attention, they look like they are designed for river or harbor protection. Very stealthy boats.