A steel shipping container may float at sea despite what anyone else in this review section may claim, so to rate this movie one star because of that is ludicrous. And here is how this works:
Containers will eventually sink as they are not completely watertight. The timespan of sinkage depends on the the type of container, its permeability and the cargo itself. Some containers sink immediately, while there are stories of containers floating across the Atlantic - in one case, taking 15 months to cross the Atlantic from the Caribbean to Spain. Once in the sea, water will enter through vents and seals. However, containers laden with lightweight, low density and buoyant cargo can float for years even when holed and waterlogged. The cargo itself may have enough uplift to keep the container unit afloat. I gathered this info from various shipping container websites.
Here's what was less realistic: Cell reception in the middle of the ocean. It IS a Dystopian world, so we'll just go with - in the future that is possible. Who knows, 25 years ago teachers told me I wouldn't have a calculator wherever I go and now we all have cell phones that prove that theory wrong.
The only serious issue that you couldn't argue away was really that mother and newborn would with almost certainty died of hypothermia.
I did laugh out loud when the whale came to "save the day." That was a bit much.
Otherwise and okayish movie. Great premise, exscution so-so. It did have its lengths and should, in my view, have been at least half an hour shorter.