How do we know their strikes haven't protected any ships, that is, preventing any strikes from happening?
Not to mention, what about the failed strikes their defence systems (against their ships) that they have succesfully defeated? They've shot down some missiles from what I remember. Or do you just mean civilian ships?
The fact that US is no longer able to project power the way it used to is very much noteworthy.
They have quite a few naval ships and planes I think Yemen right now?