Imagine similar, but technically different scenarios:
While swimming he was caught by the torrent. It put him under water, he breathed in some water, got unconscious. Some passers-by pulled him out of water, started CPR, and succeeded in saving his life.
He had planned to go swimming after work to his usual everyday place in the local river, but as he was busy at work he couldn't manage it. On the very same day the nearby dam failed, causing catastrophic flood on the very place he intended to swim. Thus he has been saved from drowning.
(added in reaction to @JanusBahsJacquet's comment) While swimming he was caught by the torrent. Fortunately, thanks to his good physical form and a bit of luck, after a long and fierce fight with the elements, he overpowered the vortex and escaped from the water on his own.
Can you distinguish the situations by a single adverb (or a single-word-like phrase)?
He nearly drowned.
He almost drowned.
He was close to drowning.
There is a related question Nearly or Almost, but not helpful for this case.