Fav place in the world is the Maldives, been about 3 times now and last year I became a qualified scuba diver. Managed to dig up a load of my mum's photos but underwater quality aint always great, these are probably the better ones.
You will discover 50 cross-water caves by boat trip, enjoy amazing landscape with fresh air, clean green water (can see the fishes around), took around 2-3 hours and very cheap price.