re: #209 CIA Reject

If that were true then you would have no way of changing the buoyant force on your body (which is proportional to the weight of the displaced fluid) and you would either always sink or always float regardless of whether you stretched out on your back or rolled up in a ball.

Um, if your lungs are filled with air, you’ll float at the surface even while curled in a ball, while drowning victims whose lungs are completely filled with water may tend to sink even if they’re “stretched out.” (Although variables like body fat also affect their buoyancy.)