Not if I can just float, which was the case for all of these people - even Bruce Briley who didn’t have a lifejacket and is seen floating on his back.
And these people are seen STANDING in the water in multiple places, so having to tread water doesn’t even apply to this situation. Rosa sometimes has her lifejacket inflated and sometimes not. Obviously she didn’t consider it very necessary - probably because she can stand in the water, as she is seen doing in multiple places in the video. Like Keith Yamamoto is seen doing right next to Fuddy. His lifejacket isn’t touching the water at all.
For that matter, it looks doubtful that HER lifejacket is even touching the water at that point, as she is laying horizontally with shoulders/lifejacket and knees above the water. That doesn’t work for normal floating. What is holding her above the water at that point - the same point when Keith Yamamoto is standing in the water with lifejacket not touching the water?
What would explain that?
And why would Loretta Fuddy be frightened enough to have an arrhythmia in water she could have stood in?
“And why would Loretta Fuddy be frightened enough to have an arrhythmia in water she could have stood in?”
That’s your fantasy. All of the underwater shots show no ground for them to stand on.