Translation:Look out! There is a whale under the water.
Do you actually say "under THE water" in VN? Because we say "underwater," and, in English, it would be pretty impossible to have a whale UNDER the water!
I agree for this case I think we would say it is in the water. Just like if there were a shark. It's in the water (in English) but I've seen this preposition used strangely (for English speakers at least) before e.g. they sit under the floor (not on the floor)
what do they mean when they say that? Do they mean that they're sitting on the floor? This is confusing to me.