No mistake at all! I happen to snorkel often and take lots of pictures. I kind of feel like I am hogging the thread if there are no other folks posting. Therefore don't post until there has been some activity. It's just been awhile since there have been any new contributions.
So please, please post as much as you like! The thread is filled with lots of great pictures and more are always welcome!.
As for vibrant colors in pictures, my secret is maximizing the natural light from the sun, an underwater setting on my camera and Google's Picasa editing software (just the "I'm Feeling Lucky" auto optimizing). If you look back a few pages there is a pretty in depth discussion on how to optimize images. I've summarized my techniques here:
TESTUDO'S SNORKEL GUIDE Cayman Off the Beaten Path, SNORKELING PICTURE TAKING TIPS AND ADVICE ...
Though looks like you do a fine job editing. The snorkelers and that shrimp are awesome images.