Take a look here: http://www.uwphotogr...rwater-settingsThat is mostly what I did with the G15.
I set up C1 for macro (including the lens zoom that gave the best magnification with some reasonable working distance, 13 cm or so as I recall). I setup up C2 for action wide-angle. 1/125s, fast f/stop, widest zoom setting, and auto-ISO
Do you have an external strobe? That would definitely change what you use for Macro.