Claudia reading your post it seems like your priorities are:
1) To take macro stills
2) An uncomplicated system
3) Keeping cost down
In all honesty as amazing as the RX100 is (and I have one) I think it sounds like the wrong camera for you. Why?
1) It does not take good macro shots (without added wet lenses, in which case it takes great shots).
2) It is a complicated camera to get to know and use, ESPECIALLY if you are new to diving.
3) It is expensive
I would suggest you look at the Canon G16 or S120.
The canons are the easiest camera to use and take amazing macro shots without extra lenses & the Canon housings are actually not bad at all and are cheap. The Ike housings are all boxy and ungainly and I just personally do not like them much at all.
So if you want a small, simple system that you can strap to your wrist and take the odd shot of some cool critter or coral then go with the Canon S120 in a canon housing. You can always buy a strobe or video light or wet lenses later on.
On behalf of the Philippine coral reef I would also highly recommend that you get 40-50 dives under your belt before you complicate things with a camera. I've just seen too many reefs being damaged by newbee divers trying to get a photo and their buoyancy is all over the place and they bash into the reef or grab coral to stop themselves etc etc.
Just my 2 cents worth.
1) To take macro stills
2) An uncomplicated system
3) Keeping cost down
In all honesty as amazing as the RX100 is (and I have one) I think it sounds like the wrong camera for you. Why?
1) It does not take good macro shots (without added wet lenses, in which case it takes great shots).
2) It is a complicated camera to get to know and use, ESPECIALLY if you are new to diving.
3) It is expensive
I would suggest you look at the Canon G16 or S120.
The canons are the easiest camera to use and take amazing macro shots without extra lenses & the Canon housings are actually not bad at all and are cheap. The Ike housings are all boxy and ungainly and I just personally do not like them much at all.
So if you want a small, simple system that you can strap to your wrist and take the odd shot of some cool critter or coral then go with the Canon S120 in a canon housing. You can always buy a strobe or video light or wet lenses later on.
On behalf of the Philippine coral reef I would also highly recommend that you get 40-50 dives under your belt before you complicate things with a camera. I've just seen too many reefs being damaged by newbee divers trying to get a photo and their buoyancy is all over the place and they bash into the reef or grab coral to stop themselves etc etc.
Just my 2 cents worth.