How do life jackets or inflateable rafts keep you afloat?
Life jackets or rafts are filled with air and operate with the principle of buoyancy. In effect, because of the pressure difference between the fluid from below and the pressure exerted from above, the raft or jacket floats.
Yes, several hundred people were clustered onto the stern section before it sank, desperately trying to find something to keep them afloat or simply too frightened to leave the ship and hoping what was left of her would remain afloat. Many of them couldn't swim, had no life jackets, and were terrified. Their sceams and wails of terror and agony haunted the survivors for the rest of their lives.