Unmanned vessels are already out there

Beware, unmanned vessels are already out there:

OK, since International Maritime Law doesn’t yet allow vessels to be unmanned when operating in international water there will be a minimum manning for the time being.
But for how long? The technology is already there and more and more such vessels are being built for survey purposes.

PS> The US Navy is keen to explore the possibilities of unmanned fighting vessels and they don’t necessarily worry too much about International Maritime Laws.

What is the point of having manned vessels when this still happens?

What happened? Any stories about this?