My roommate's dad in HS was the Secretary of Defense back in the 1970's (James Schlesinger) and I remember him telling me that ships inadvertently come within 1

My roommate's dad in HS was the Secretary of Defense back in the 1970's (James Schlesinger) and I remember him telling me that ships inadvertently come within 1/4 mile of hitting each other all the time. That seems pretty close when you're steering a giant aircraft carrier. Of course, that was along time ago, but still...doesn't seem like much has changed.