Kefalonia-Lake Melissani

Wow, that is a beautiful place! I really like seeing clear water ("daylight") under the closer boat.

This has to be a really hard shot to get right. You've got the full daylight up above, and the dark cavern, the subject you actually want to shoot. I'd have panned this shot a little further down, putting more emphasis on the water and cropping out the sky entirely. Getting rid of the sky will also leave the depth of the cave unknown, a mystery, adding to the magical feeling this shot could create. Your shutter speeds will slow down DRASTICALLY with this, and it may require a seriously strong diffused flash. I'd love to spend some time in there getting it right, though. Great location.