Hey Interceptor, thanks for your comments.
1. For years I looked with admiration at these black macro shots, when all my friends were producing were top down shots with lots of sand etc in background, so I wanted to "master" the effect and get my black background technique down pat. I think I'm about there now, and will definitely begin experimenting more on my next trip (well I'm going to Maldives next, and I'm going to try 90% W/A). It's relatively easy to take all the "standard" shots like these (which require little skill or luck), but the real killer ones with incredible moments caught in time or very unique compositions take real creativity and patience, so for macro at least, that is the next level.
2. Interesting comment on colour punchiness, to my eyes and preferences it looks okay. Yes I shoot RAW and can always bump up the saturation or vibrancy in post, but actually in some cases I reduced it slightly because I felt it looked a little too artificial. Maybe it's a beauty in the eye of the beholder thing? But interesting you would say that. I was advised that if I ever intended to print anything, I should really bump up the saturation for the print version, but for screen it's not so critical. Any thoughts on that?
Thanks!