That's the biggest question I have. How did this tragedy occur with all the backups in place on the Navy destroyer? Sure, the aft lookout could've been asleep. The starboard bridge wing lookout could've been training a new lookout, and could've been drilling them with questions--or, maybe they were discussing how the Cavs would do next year if they drafted traded for Paul George. They're human, and they're young...surely, someone more senior would ask them about any visible contacts before they became a problem.
One surface watch petty officer in Combat might've been re-reading a hot text from his girlfriend, and maybe he saw a surface contact, but this was a busy shipping lane, and there were LOTS of contacts around, but nothing he noticed as a threat. Besides, there were others on watch, too.
Maybe the OOD noticed the contact, or maybe a new JOOD was being trained, and they were busy with questions. Maybe they got a call from the Engineering Watch Officer, asking for permission to take down a generator for unplanned maintenance.
Someone in CIC might've asked the bridge if they had a visual on surface contact bearing 030, and they may have responded in the affirmative, without actually processing its meaning.
The bridge and CIC teams should work in orchestrated unison, each providing backup to the other, should any one player make a small mistake. For all of them to fail simultaneously requires an extreme amount of bad luck or bad decision-making.
Dont the radars on ships have a “Bitchin’ Betty?”
For goodness sake, most cars come with collision avoidance tech on them.