It’s a new metaphor to me – public relations is like a submarine: covert but powerful. This essay provides a useful analysis of how PR helps make the news:
A good flatterer doesn’t lie, but tells his victim selective truths (what a nice color your eyes are). Good PR firms use the same strategy: they give reporters stories that are true, but whose truth favors their clients.
It also correctly identifies that public relations is a particularly potent tool for small business, who often can’t afford to advertise.
Thanks to Corporate Engagement for the link.
PR Studies 
Nope. Not good PR. Lazy PR. PR has to be about engagement.
Submarine PR is the slippery slope towards unethical practice.
The practitioner must have a foot in both camps and that requires trust. Submarine PR is about being a mouthpiece of the dominant coalition. Good PR makes the dominant coalition face the truths and so (to keep the metaphore going) I am in favour of lighthouse PR.