I've got this not-too-hard Scifi setting that has a race of snake people, inspired by boa constrictors, that live in a Amazon-like forest near the riverbank and have affinity to water and swimming. (but no, they can't breath underwater) They bury their eggs (which are hard shelled, like a sea turtle's), and then usually don't check on them much till the day they are due to hatch.
Let's say river flooded and submerged a clutch with about 4-7 eggs mid-way during development for about 24 hours. Is there any scientifically plausible way to explain why (at least) one of them survived being so long underwater and still hatched a somewhat healthy snakeling?
Would it be plausible to the eggs being equipped with internal air-sacs to keep the embryo oxygenated if something like this ever happened? Since they are a semi aquatic species and lay their eggs on river banks, I suppose that would be somewhat plausible from a evolutionary point of view, but I am always open for better (and more scientific accurate) ideas.