A regular, if not hackneyed, feature of adventure and action movies, TV shows, and comic books is quicksand. It is unusually found by some foolhardy or overzealous traveler deep in a jungle, swamp, desert, or other forlorn location. Once the sinking begins, it is irreversible and trying to get out only aggravates the predicament. The unfortunate victim slowly succumbs to death by suffocation. Sometimes a hand or hat remains for dramatic effect once the soon-to-be-deceased goes under.

These portrayals represent a mythological version of quicksand, but the phenomenon is real and in certain instances and situations, can be hazardous.

Geologically speaking, quicksand comprises sand, clay, and saltwater, and it appears and acts as a solid. But when weight is applied, the mixture begins to collapse. It most frequently is present where there is upward-flowing water, often near rivers or beaches where liquid is right under the surface. When disturbed, the mixture transforms from a loose packing of sand on top of water into a more dense liquid. Its high viscosity creates resistance and suction, and the more stress that is applied, the more liquid it becomes. So thrashing about will indeed cause a trapped person to further sink and become more engulfed. But this will only make the situation temporarily worse. On an average-sized person, quicksand will be, at the most, about waist-deep.

The key is to stay calm and eventually float to safety. Experts advice stretching out on your back to increase your surface area and waiting until your legs break free. It is also suggested to move one’s legs around at this point, to stir in water, which will help you float.

While that works for people, quicksand can pose a threat to horses, who upon encountering it, may panic and exhaust themselves while trying to break free. It requires specialized equipment and sedation to rescue them. And it can still be hazardous for humans, especially if one is hiking alone and being unaware of these extraction techniques.

So if starting to go under a la an Indiana Jones flick, get rid of anything you are carrying. Next, distribute your weight by lying backward since staying motionless may increase the material’s viscosity. Trying to extract a leg by pulling it means working against a vacuum left behind. A better tact is to rock back and forth, thereby creating a space for water to move into. This will loosen the material around your limbs. Instead of being sucked all the way in, quicksand victims will float once they get about waist deep. That’s how it works, though it would make for a boring movie scene.