If you are currently standing in a changing room, dripping wet, holding a towel over your waist, reading this on your phone because you don't know what to do—take a deep breath.

The immediate aftermath is characterized by a distinctive psychological arc:

Another factor to consider is the Venturi effect. This phenomenon occurs when the velocity of a fluid (in this case, water) increases as it passes through a narrow space, creating a region of low pressure. If you're swimming near a structure like a pier or a rock, the water flow can accelerate, creating a region of low pressure that can suck off your trunks.