For watersport athletes and enthusiasts alike, safety is always the top priority. Sports like kayaking, downwind paddling, and sailing carry real risk from prolonged exposure to unpredictable elements. Wearing a life jacket, or personal flotation device (PFD), is one of the best ways to dramatically reduce the chances of drowning and injury. But how do they actually work, and how do you know when yours needs replacing? Let's find out.
How Does a PFD Work?
PFDs use the principle of buoyancy to keep you afloat, unassisted. Buoyant material traps air and makes the wearer less dense than the water around them, so the water exerts an upward force that keeps you at the surface.
A well-designed life jacket distributes your body weight more evenly across the water's surface. Some designs concentrate buoyancy around the head and chest to keep an unconscious wearer face-up and protect their airway, though this face-up capability only applies to higher-buoyancy designs, not the low-profile Level 50 PFDs used for most performance watersports.
Foam vs Inflatable PFDs
The two most common types of life jacket are foam and inflatable:
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Foam PFDs are the choice for athletes and inshore watersport enthusiasts. The buoyancy is always there, with nothing to trigger or maintain, and the foam doubles as a layer of impact protection. All Vaikobi PFDs are foam. Foam PFDs are lighter, softer and more comfortable than inflatable PFDs.
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Inflatable PFDs are more common among boaters and offshore sailors. They're compact until activated, then inflate via a trigger, either a manual pull-tab or an automatic reaction on contact with water. They typically offer higher buoyancy (150N or more) but require regular (annual) servicing to stay reliable, and they don't suit high-mobility sports where you're frequently in and out of the water. Inflation style PFDs can feel stiff and bulky around the neck, and can be prone to self-activating / self inflating by accident if not maintained properly.
For paddling, sailing, surfski, and foiling, an inherent (built in) foam PFD is the most practical and easy to wear option that does not require annual servicing , which is why every PFD in the Vaikobi range is foam-based.
Impact Vest vs PFD
You may also come across water sports impact vests, which look similar to a PFD but do a different job. An impact vest is designed primarily to absorb impact during high-speed falls, and while it provides buoyancy, it isn't a certified flotation device the way a PFD is. A PFD is certified to keep you afloat; an impact vest is built for crash protection with some buoyancy. Which you need depends on your sport and whether certified flotation is a priority. For the full breakdown, read our Water Sports Impact Vest vs Certified PFD guide.
Understanding Buoyancy Levels
Buoyancy is measured in Newtons (N), and PFDs are classified by how much they provide, from Level 50 up to Level 275. Level 50 is the standard for active watersports like paddling, sailing, and foiling, providing 50 Newtons of flotation with the freedom of movement these sports demand. Higher levels (100, 150, 275) provide progressively more buoyancy for offshore and rough-water use, and are designed to turn an unconscious wearer face-up.
All Vaikobi PFDs are ISO 12402-5 (Level 50) certified. For a full breakdown of each level and how much buoyancy you need, read our guide to PFD buoyancy and performance levels.
How Long Does a PFD Last?
Knowing when to replace a life jacket is essential. For dinghy sailors, paddlers, or foilers who wear their PFD weekly, foam life jackets should generally be replaced after around 12 to 24 months, or sooner if they show significant wear. Foam PFDs used less often, stored on yachts or larger vessels, don't need replacing as frequently.
Inflatable PFDs should be serviced annually by a professional, checking the bladder, CO2 cylinder, reflective tape, buckles, and straps.
How to Test if Your PFD is Still Safe
Foam life jackets don't carry official expiry dates, but there's a simple in-water test to check whether yours has degraded. (For more information, read our guide on whether life jackets have expiry dates.)
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Check for visible signs of wear or damage: tears in the outer material, mold, significant discolouration, or weak stitching. If any are present, replace it.
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Find a low-risk testing area, such as waist-deep water at a pool or calm beach. Put the PFD on and secure it firmly.
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Slowly submerge and lift your feet off the bottom. If you have to actively tread water to stay up, the foam has degraded and the PFD is no longer safe.
Inflatable and self-inflating PFDs are best serviced and checked by a professional.
How to Care for Your PFD
Getting the most life out of your PFD comes down to simple care: rinse it in fresh water after every use, dry it in the shade rather than direct sun, never store it damp, and don't crush or fold the foam, as maintaining its shape is what keeps it buoyant. For the full routine, see our complete gear care guide.
Make Sure Your PFD Fits
A PFD only works if it fits correctly. Too loose and it can ride up over your face or slip off in the water; too tight and it restricts the movement your sport demands. Vaikobi recommends sizing by chest measurement rather than weight, and adjusting the straps so the jacket sits firmly against your chest without riding up. A well-fitted PFD should stay put when you lift your feet in the water, and feel so comfortable you barely notice it's there. For step-by-step help, read our PFD fit guide.
Find Your PFD
In search of a new life jacket? Explore the full range of Vaikobi PFDs and life jackets, all foam-based and ISO 12402-5 certified, built for the freedom of movement that performance watersports demand. Need more info? Check out our blog on the full range of Vaikobi PFD's.
