same same.
i tried swimming in a deep pool, though my height exceed the water
limit of the pool (means i'm taller then the depth of the water)
without doing proper warm up. and i have short breath, cant swim
long. and sway sway, reach the middle of the pool, exhausted leow.
leg cramp, but contiuned to swim.
then sway sway, reach the depth of 1.7m leg cramp no breath leow.
gasping for air up and down, cause leg kicking about.
and yes, i nearly died. 
summary: always do warm up before swimming
