Something similar happened to me as a kid, I decided to swim from our boat to the shore of the lake, got exhausted 100 meters from the shore. Before going in full panic mode I remembered you can basically float indefinitely on your back with very minimal effort and did just that until I was calm and rested.
Turns out our mandatory swimming lessons from the age of 8 weren't as useless as I thought.
Turns out our mandatory swimming lessons from the age of 8 weren't as useless as I thought.