Oh I know. The Pentagon is trying its best to deter what is known as the "ship based threat" (see missilethreat.com). A tactic the Iranians would use (they test their Shahab missiles from ships too). They were the ones who came up with the idea of putting a SCUD on a freighter then sailing it to a nation's coast as well.
For their local neighbors, they'd put a nuke on an aircraft, fly it over the target, and detonate over the target.
Nothing fancy, but darned effective.
I asked someone to imagine the mayhem on 9/11 if it had been a nuke on a container ship instead.
Didn't get an answer on it.