The human body has a lower density than water, causing it to initially float when submerged. However, as water enters the body, its density increases, causing it to sink.

The expansion of the body due to additional water further increases the total volume, leading to a decrease in overall density.

This phenomenon occurs because the weight of the displaced water surpasses that of the body, causing it to float again. This principle is applicable to the buoyancy of various objects as well.