It's rather bizarre isn't it? Not just the failure to maneuver safely in the presence of another ship, but also the fact that whatever sensor technology they have didn't alert them or was ignored. Pretty much every modern commercial vessel these days has AIS and collision avoidance, I'd imagine naval vessels have _at least_ that. Just an odd thing all around, and to have it happen twice is either a hell of a coincidence or there is indeed something systemic at work.

A factor in the McCain collision will likely be the merchant ship's over-reliance on AIS and radar and not getting a visual check before turning into the path of fast-moving ship that a.) doesn't use an AIS transponder, and b.) is purposely hard to see on radar. There will be certainly enough blame to go around to hit McCain's leadership, though. ("They should have known that the merchant couldn't see them well and been prepared for yadda yadda.")

The Fitzgerald collision, however, is a real mystery...

Good points. I would also have expected that they'd be in radio communication maneuvering that closely to a large merchant vessel in a busy seaway.

FWIW, US Navy ships don't broadcast on AIS, though they monitor it. That means the other vessels around them have to look out the window to notice them (or get hailed on radio.)