while reading this thread, I get the impression that in water image manipulation seems to be ok, while out of the water is not. Also there seems to be a lot of argument about what is purist and real and what is manipulation.
Maybe it wouldn't hurt to remind ourselves that photography, even film, from it's humble beginning, had very little to do with realism. People are just constantly pushing the boundaries of what is possible. I don't seriously think anyone is going to ask about wether any image has been processed by a computer in a couple of years, it will be implicitly assumed. To that end, I think you won't know what a digital camera has done to your shot without telling you pretty soon. A quick flick through my Nikon advanced menus reveals noise reduction and other image manipulation built in....while I see nothing wrong with that, I'm sure that is a trend that is going to intensify in future models.
I also don't get the whole skill debate. In water manipulation with a digital camera is photographer skill and photoshop is not? I guess this is an emotional subject. Things the photographer does when, or closely after shooting, or multiple attempts, give them the feeling of investing work into the picture when it's taken, or close to that time in the case of multiple shots (nobody ever said that was unethical right?). It is personally rewarding and satisfies people's artistic streak, i.e. the emotional reward of being more in control of the picture the moment they take it. It gives the photographer a more intense feeling that it was "them" who took the picture. Easy to feel threatened when that can be done in a different way.
With UW photography being one of the traditionally most highly manipulated areas of photography anyway, no light without massive strobes, color adjustment to make the light look like at the surface, to name a few I just fail to see the point? Wide scapes of blue green, badly lit water are boring...nobody would bother shooting it.
It's not what is there, it's what you make others see.