They were worried about spies, and sabotage, right thru the cold war. Don't go up the Housatonic River to the backside of Sikorsky Aircraft, you won't make it far. There are marker buoys, and patrol boats, and they are armed. Likewise up the Connecticut River where General Dynamics builds the nuclear subs, (it's pretty wide there, you'd have to be an idiot to navigate close to the clearly visible subs), or the clearly visible ( and not visible) armed guards or General Electric, or any of the defense companies headquartered in this state. Pratt and Whitney is like a city unto itself!