The illustration friday word is ‘swamp’. I’ve gone with the verb rather than the noun…
1. To drench in or cover with or as if with water.
2. To inundate or burden; overwhelm: She was swamped with work.
3. Nautical To fill (a ship or boat) with water to the point of sinking it.
Here a capsized man knows to use his own air pocket to breath…I like the thought of us being like upturned boats sometimes though with that little bit of air trapped at the very top of us.