Life Vest vs. Seat Cushion: Which Will Save You? (VIDEO)

On a recent airplane flight, I noticed something disturbing. And no, I don't mean Sky Mall's Garden Yeti now costs 20% more. I'm talking about the flotation devices. Or, better yet, the lack thereof.

Did you know that all passenger jets in the US are required to have seat cushion flotation devices? They are. However, only those passenger jets that fly more than 50 miles off the US coast are required to carry life vests. This means that the near countless domestic flights that land at coastal airports or whose routes take them over water -- flights from NY to Miami, or Los Angeles to San Francisco -- are not required to provide passengers a life vest flotation device.

As the producer of This vs That, a new series that conducts scientific inquiries into everyday questions, the details of the flotation devices got me thinking.

Suppose I was a passenger in a plane that experienced a catastrophic failure over water. I survive the impact. Amid the chaos and devastation, I have the where-with-all to grab a flotation device. Which one is better suited to aid in my survival, the life vest or the seat cushion?

The FAA defines a "ditching" as "a controlled emergency landing... in water." As opposed to a "crash," which connotes a plane spiraling out of control and smashing apart on impact - with few to no survivors.

Around the world, there have been 14 ditchings of passenger jets since 1952. There were 834 people on board those 14 flights. 573 of those people survived. Of those that died, most died on impact. However, many impact survivors later died in the water from hypothermia.

In 2005, Tuninter Flight 1153 crashed 18 miles off the coast of Sicily. There were 35 passengers on board, 15 died on impact. Twenty survivors languished in the ocean for 46 minutes before being rescued. Thankfully, the water that day in the Mediterranean was in the 70s.

The temperature in the Hudson River on January 15th, 2009 wasn't as pleasant. The day US Air Flight 1549 ditched in the Hudson, the water temperature was 41 degrees.

At 41 degrees, the human body can withstand the initial shock and onset of hypothermia for approximately three minutes. After which, survivors become increasingly disoriented. Next, they will thrash around and begin to shiver. Teeth will chatter... they will lose body heat... and begin to lose the ability to have normal thought processes, becoming increasingly less lucid.

In the field of Airline Emergency parlance, this inability to think clearly is known as quote: "Going Busey."

Continued exposure to frigid water will next lead to the loss of fine motor skills, followed by the loss of the shivering reflex and the body's ability to retain warmth.

As the time survivors languish increases, as exposure to frigid water increases, hypothermia gets more severe, muscle coordination rapidly decreases, and then a survivor's ability to perform muscular activity decreases to the point of cessation. Hence, those passengers who have been desperately clutching a seat cushion flotation device will no longer be able to do so.

As survivors thrash about, they will next experience excruciating cramps followed by the complete inability to keep themselves afloat. Soon enough, survivors are no longer able to keep water out of their mouth, the core temperature in their body comes down so low, it causes a heart attack and you die.

In an emergency situation in cold water, someone with a life vest is at a greater advantage than someone who has to grapple for a seat cushion, take the coordination to put their arms around the device, lock it in, and then hold on and not let go.

Jon Hotchkiss is the creator and EP of This vs That. "Like" This vs That here in order to be among the first to know when new episodes premiere.