The personal flotation device might not seem like a lot, but that thing has saved countless lives. In fact, statistics have found that PFD’s have prevented over 90% of potential fatalities in accidents where boat passengers fall overboard. But for as effective as the PFD might be, it’s inherent benefits are only going to be as good as its buoyancy.
Contrary to popular belief, PFD’s don’t last forever. In fact, they can lose that buoyant property and become a potential hazard as time wears on. So what is the best way to check the buoyancy of your PFD? Read on to find out.
Different PFD Classifications
The US Coast Guard has a rating system that tells you what specific activities and conditions a PFD should be good for. As of writing, there’s 5 different types, and these include:
I - Offshore Life Jacket
Suitable for any types of water, especially where rescue might be delayed
II - Near-shore Buoyant Vest
Use in tranquil inland waters where there's a high chance of a quick rescue
III - Flotation Aid
Use in inland waters that are calm and where there's a high chance of a quick rescue; will not turn an unconscious user face up
IV - Throwable Device
The purpose of this is to be launched to an individual who might require flotation support on the water
V - Special Use Device
This is specific for sports and water activities like kayaking or windsurfing; some may provide protection against cost
What is Buoyancy and Why Is It Important?
Buoyancy is essentially the tendency or the ability of something to float in water. The higher the buoyant force of a PFD, the more capable it should be to keep you afloat. Over time, the materials that make up your PFD can degrade for a variety of reasons. That’s why it’s important to keep an eye on buoyancy to make sure your PFD can still serve its purpose.
Generally speaking, the main force that will work against buoyancy is the wearer’s weight. If the individual wearing the PFD is too heavy, then it’s possible to negatively affect the buoyant force of the flotation device and may even render it useless all together.
How Can You Know If They Will Float?
It’s not enough to just toss your PFD into the water to determine whether or not it will float. Remember that the force of the wearer’s weight will have tremendous impact on the device’s ability to float. So you’re going to have to try something more than just throwing it in the waves and seeing if it stays on the surface.
To measure the buoyant force of your PFD, you’re going to need a weight that’s at least 10kgs. Attach it to a cable and secure a luggage scale on the other end to measure the weight. Submerge the weight in water until it’s completely under the surface, then read the weight on the luggage scale.
Then take your PFD and secure it around the weight. Following the previous step, submerge both the weight and the PFD. Measure its weight using the luggage scale. This should reflect a lower number than the previous reading.
Now take your first reading and subtract the second from it. So if your first weight was 9.2kg and the second was 1.6kg, you should come to a final measure of 7.6kg. This gives you the measure of the PFD’s buoyancy in kilograms. To convert to Newtons, simply multiply your answer by 9.8. Thins brings your final measure to 74.48N.
To determine whether your PFD still provides the buoyant force expected of its type, refer to these measures:
Buoyant Force in Pounds
(kg x 2.2)
22lbs of buoyancy for adults; 11lbs for kids
15.5 lbs for adults; 11lbs for kids; 7lbs for infants
Same as type II
What is the Best Way to Put It To The Test?
If you’re testing a PFD for buoyancy, the last thing you’d want is to find out it doesn’t work while you’re out in the open water. So if you were planning to test your device, it’s important that you find a controlled environment for the task.
A shallow swimming pool or the shore of calm inland waters should be ideal for the process. Wear your PFD and wade out so that the water is about chest deep. Then bend your knees towards your chest so that your chin is just above the surface of the water. Lift your feet off of the ground to see how well the PFD can keep you afloat.
Move around, kick, and wave your arms to check if the device will stay in place. This should also give you the chance to see how well the PFD will keep you afloat even in less than ideal conditions.
If you struggle to keep your head above water, or if your face dips under the surface too often that you find yourself struggling to breathe, then it might be time to find a replacement.
Other Ways to Test for PFD Buoyancy
While it isn’t recommended, some experts say that you can really put your PFD to the test by attempting to fight against its buoyant force. You can do this by trying to swim under the surface while wearing the device. If it forces you upwards and you struggle to stay underwater, then that could be a good sign of intact buoyancy.
Another way to perform a quick test on your PFD would be to pinch the material. Non-inflatable devices use a foam material that you can pinch and squeeze to determine the integrity of the PFD. If it rebounds quickly to restore its original shape, then it’s still in good condition. But if it takes a while to return, or if the material stays depressed all together, then that might be a sign of poor performance.
Don’t Forget to Check Your PFD
The PFD is a simple device that has saved numerous lives. So if you want to minimize the chances of accidents out on the water, it would be wise to have a PFD for everyone on board. But since those things can wear out, it’s important to ask - what is the best way to check the buoyancy of your PFD? Follow these tips and tricks to check your flotation device and make sure that it serves it purpose out on the waves.