Yes, that is quite correct, Mr. Jean. This is by no means attempting to somehow preclude the application of general law. The principles are still there.
As to your point about persons being lawfully on board, I suppose that's probably indeed the case. For ship inspectors and folks like that who might have business on board, for example, it is at least implied that they are allowed to be on board. Arguably, it's a bit different from someone who sneaks on board to get passage, which is the stowaway type of problem.