Once you are aware that a female has nested it is important to dig the eggs up as soon as possible. Chances are if she liked the spot where she laid the eggs another female many feel the same way. I have lost several clutch over the years because another female nested right on top of a clutch of eggs.
Carefully remove the sand from around the eggs and then remove the eggs from the nest. Place them into a container with a substrate (I use Hatchrite). I bury the eggs only halfway in the substrate. NEVER tilt or turn the egg from the original position that it was laid in, otherwise you may kill the embryo.
I have had some success with hatching eggs that were laid in the water. Incubate them just as you would an egg that was nested normally. You might get lucky and it may hatch.