No fear, actual real mechanical hardware. Mach 10 cruise missile, which is 7500 MPH. Surface radar might pick it up about 25 miles away, skimming the surface of the ocean for an attack on an aircraft carrier. That's only 12 seconds till it hits it's target. Really good human eyesight might see it at 2 miles, and that's less than one second from striking. And it wouldn't be alone, they would be launched in groups, and in probably three multiple waves of them. Serious weapon... edit: it's moving so fast it would try to glow bright red from heat. It would be like getting hit with a large meteorite. If it missed and hit the water, the shock wave in the water at that speed would be enough to sink most ships. (If it weighed at least 500 pounds.)