The intertidal snails will eventually learn not to climb out. But certain species like these that do spend a lot of time outside the water will take a lot longer. Be prepared to pick them up from the floor, under the stand, behind the pipes and other places where they can go in but not your hands. If you got a rimless tank, forget about them. You will eventually give up putting them back and they will die outside your tank after too long exposures.
Some juvenile snails stay above the mark to minimize the time they are exposed to other predators. Be it fish or hermits. They can stay on the rocks during high tide, being slammed by waves. But hermits can not.