Re: Underwater photograpy..newbie to it
Hi Tim,
just realized that you really meant "snuba", while I had taken it for a typo, think you meant "scuba".
So, let me shortly tweak my answer:
As you have figured out yourself, an additional light source at max. 6m depth is not necessary. You will mostly shoot with ambient light and additionally use the internal flash of the camera. From my own experience I would think, that you will take mostly wide shots of the reef and closer shots of certain coral blocks and fish, turtles etc., but not too much real macro.
Therefore, I would make sure that you are happy with the autofocus speed of the camera (the new RX100 seems to be the best in that class). Fish are unfortunately not very cooperative and annoying, I have a nice collection of fish tail pictures.... You said, that you had the Canon G10, well, I had the G9 and it was hell shooting underwater due to the slow AF...
Just one more suggestion, when we snorkel, or dive shallow, we tend to take our subjects from above, I did this a lot in the beginning. While there are some compositions that are beautiful that way, generally speaking, you will find that being level with your subject or shooting from below to have an uncluttered background will improve your composition. That will mean that you will have to free dive a little when you are snorkeling (so no wearing a stupid lifewest as some people do in my region).
...and last, but not least: I mentioned the glare on the LCD screen in shallow waters, try to get a LCD Screen Hood (somethinh like that: https://www.getolympus.com/us/en/accessories/camera/underwater-housings/lcd-hood-for-pt-057-underwater-housing-pfud-057.html
it will improve your experience quite a bit.
So, that's it...
Enjoy!
Lars