We wrote recently about the collision between a U.S. Navy destroyer and a Philippine-flagged container ship in the sea off Japan. A more thorough discussion of how the collision might have occurred can be found at the National Public Radio website.
The most important thing NPR adds to what I'd written previously is the details of how, in a congested and busy waterway, too many moving objects can overwhelm the ability of those plotting them to keep track. And we now know there is a possibility the container ship, after midnight local time, was proceeding on autopilot.
Find even more info on "the rules of the road" for ships - who is supposed to give way when two ships near each other - in a piece written by a former ship captain for War on the Rocks. He concurs with my view that human error on one or both ships likely played a role, how large a role is yet to be determined.
N.B., The vessels involved were of course ships, not smaller "boats."