Are you an excellent swimmer? Even if you are, the humble life jacket is an essential piece of equipment. It has saved countless lives before. It can even save your life someday.
What are life jackets made of? Life jackets most commonly consist of an outer shell and inner foam designed to provide buoyancy. The outer shell is typically manufactured with either nylon or neoprene, depending on the intended use. If the life jacket uses inner foam, it consists of a material called closed cell foam, which is both lightweight and water resistant.
Have more questions about what you need to know when learning about life jackets? Luckily, we’re going to answer them all today in this post. Hop on in!
What Is a Life Jacket?
Like clothes, life jackets are available in different sizes and types to accommodate different kinds of people. They’re even available in a range of styles, and they’re noticeably lighter than the life jackets of past times.
Modern life jackets are available for those interested in boating, kayaking, fishing, and canoeing. They’re also available in commercial transport ventures, such as coastal cruises and overwater flights.
But what exactly is a life jacket?
Simply put, a life jacket is a piece of safety equipment designed to keep a user safe when on a body of water. Much like how a safety helmet protects its wearer’s head from trauma, a life jacket protects its wearer’s body from drowning.
“How?” Well, by keeping them afloat in water, even if they’re unconscious.
Some of these life jackets are even supplied with a whistle to call attention in an emergency situation. They’re even sometimes outfitted with a light, which may be triggered upon making contact with the water.
What Is a Life Jacket Made of?
We’ve undoubtedly come a long way from animal skins and cork.
Nowadays, plastic foams, such as those made from polyvinyl chloride and polyethylene, are all the rage. These materials are inherently buoyant, meaning you don’t need to activate the flotation yourself. When the life jacket is submerged, the flotation is automatically activated by closed cells inside the jacket.
Other types of jackets employ different ways of flotation. Inflatable life jackets are marked by the carbon cartridges sewn into their insides. These cartridges release gas into the life jacket, causing them to inflate quickly once deployed.
The outer layer of a life jacket is usually either made of nylon or vinyl material. You’ll find that most life jackets stand out due to their vibrant colors, like yellow, lime green, or bright orange. After creating a pattern design, this nylon is rolled out and cut either automatically or manually.
Nylon jackets also dry quickly, and they’re not as expensive as neoprene life jackets. They tend to be the most common type of life jacket available, and surely this kind of life jacket is what the general public thinks about first.
Visually, neoprene doesn’t look that much different from nylon. However, all it takes for you to notice the difference is to touch a neoprene life jacket: they’re much softer than nylon life jackets, and they bend more easily. This little feature makes them ultra-comfortable to wear.
If you take part in watersports frequently, then you should consider purchasing a neoprene life jacket. These jackets are made for activities like water skiing and waterboarding. After all, they keep you warmer in the water.
Neoprene life jackets take a little longer to dry. They might be more expensive, but they’re also more durable when compared to the typical nylon life jacket.
The inside of a life jacket is typically made of closed-cell foam (I say typically, as inflatable life jackets do not contain this foam). This foam doesn’t absorb any water, and it’s ultra-light, so it keeps its wearer from drowning. Needless to say, it displaces a lot of water compared to its weight.
After a pattern design is decided, the closed-cell foam is rolled out and cut, just like the nylon.
Finally, sewing professionals sew everything together. They finish off by inserting the foam through an open seam, then sew the whole thing shut.
A Look at Life Jackets Throughout the Years
Life jackets might seem like a “modern” invention, but they’re not. They’ve actually been around for longer than you think.
Historically, people fashioned life jackets from animal skins. The earliest record that could be found of life jackets is from 870 BC: when Assyrian king Assur-Nasir-Pal’s armies needed to cross deep moats, they used inflated animal skins to keep them afloat.
The first modern life jacket was invented in 1854 by Captain Ward, a Royal National Lifeboat Inspector (RNLI). He cycled through many materials like air, horsehair, wood before finally settling on the cork. At the time, cork proved to be the only material reliable enough to use. It provided both buoyancy, durability, and water resistance.
What Makes a Life Jacket Float?
So how does a life jacket work? The answer is easy: buoyancy.
Now, you might already know that an object high in density sinks in water, while an object low in density floats. Archimedes, the ancient Greek philosopher, had something interesting to say about this occurrence.
Here’s what Archimedes observed: when you drop an object in water, the water will react by pushing the object up. This isn’t all: the water will push this object up by a force equal to the weight of water that the object displaces.
In simple terms, buoyancy is the force that pushes an object upwards, keeping it afloat. It’s measured by weight.
It’s why humans feel lighter in swimming pools. The more water an object displaces, the greater the force pushes back.
Now, if an object displaces an amount of water equal to its weight, it’ll float. The upward push—the buoyant force—from below will keep it afloat.
Your body’s density is close to that of the water. To float, a human needs only 7 to 12 lbs of buoyancy. A life jacket more than easily provides that support.
When submerged in water, the material of a life jacket fills with air. This air weighs less than the water displaced by the life jacket. In turn, the buoyant force keeps the life jacket up.
Life jackets differ depending on how much weight they can support. Adult life jackets provide a buoyancy of 15.5 to 22 lbs. A child’s life jacket provides less.
How Long Can a Life Jacket Keep You Afloat?
Even though life jackets should be able to keep you afloat indefinitely, most search parties only last a few days. This is because most people don’t have access to fresh water or food after going overboard, so they’re likely to die within 3 days.
Life jackets aren’t magic. A person can drown wearing one, especially if they’re in rough waters.
Cold-water also forms another threat: if someone is submerged in waters below 26 degrees, they could get hypothermia.
These days, life jackets are made from foam and nylon and may also include closed cell foam if they are not the inflatable kind. But they still serve the same purpose they did all those years ago: keep people afloat, and save lives.
We can safely say they succeed in doing both. Not only that, but they also manage to be comfortable and light, making them much more desirable to wear than their earlier (and heavier!) ancestors. So they’re not only lifesavers, but they’re pretty comfy, too!