termarks
I have been pulled aside once just so they could swab it, but my CPAP is mostly ignored by the TSA. I'd imagine they see enough gray ResMed bags that as long as it get scanned, it's nothing special.
They give you a basic swim test, administered by Navy SEALs. It involved (at the time, mid-90s) jumping from a 25ft high diving board into a pool, and treading water for a bit. This simulated having to dive over the edge of a ship in case you had to evacuate.
Anyway, I climb up, get to the edge of the diving board and just freeze. A very unhappy SEAL actually had to climb up and push me off the board. I must have been a really sad, pathetic case because one of the other SEALs doing the training pulled me aside and worked with me for the remainder of the day so that I could pass the swim test later that afternoon.
Kinda makes me wish I had learned when I was a kid, or had the time to learn now. At least I can still tread water.