Spending time near the water this summer? Here's when you need to wear a life jacket and how to find the right fit.

No matter how good a swimmer you are, there are going to be times you’ll need to wear a life jacket. In fact, you probably need one more often than you think. These life-saving devices aren’t just for emergencies — they're considered standard practice for a number of water activities.

So when should you strap on a life jacket? What signs tell you that a life jacket isn't safe to wear? And are things like swim vests, or even water wings for kids, just as good? Here’s what experts have to say.

What is a life jacket (and how is it different from other personal flotation devices)?

There’s some confusion out there as to what constitutes a life jacket, vs. a general personal floatation device, so here’s a quick breakdown.

According to the U.S. Coast Guard, a life jacket is a personal floatation device that provides buoyancy whenever you’re in the water. Life jackets (sometimes also referred to as life preservers) will help you float even when you’re unable to do that yourself, whether that's because you’re a weak or non-swimmer or are too cold, too tired or injured. As the recreational retailer REI describes them, they literally keep your head above water in order to save your life. These life jackets are classified as Type I personal floatation devices (the other classes are Type II, Type III and Type V).

The Coast Guard classifies personal floatation devices (PFDs) into two categories: life jackets (whose job is to keep your face up out of the water), and buoyancy aids (which require users to swim or at least move in certain ways to keep their own face out of the water). Additionally, PFDs are divided into four categories: inherent, inflatable, hybrid and special purpose. Each of these is designed with some safety features in mind and is meant for activities (such as kayaking) in which there may be some risk but are not likely life threatening. Unlike life jackets, none of these will keep your head totally above water while you are unconscious.

Items like swim vests might offer some level of protection, but they are not life jackets. Puddle jumpers are certified by the U.S. Coast Guard, but, again, are not considered life jackets. Inflatable arm bands, aka floaties, are not Coast Guard-approved. All that said, experts say none of these items should ever be mistaken for life jackets and should only be viewed as layers of protection against drowning, and not as a substitute for proper supervision and swim lessons.

Who needs a life jacket, and when?

“Life jackets are really designed to be worn every time someone's not expecting to go in the water but could find themselves in the water, such as falling off of a boat,” says Adam Katchmarchi, CEO of the National Drowning Prevention Alliance. He says that even goes for simply hanging around a dock or pier, particularly if you’re a parent or guardian worried your child might potentially jump or fall off.

“If you're going into an undesignated swimming site or you're recreating with your family around at a lakefront rental property, having kids in life jackets is always a great idea,” he adds.

The Coast Guard also recommends wearing a life jacket while water skiing or participating in other towed activities, operating a personal watercraft or taking part in white water rafting and sailboarding or windsurfing. Even if you’re an excellent swimmer, these activities can sometimes result in injuries or other emergencies, so it’s best to be prepared.

Life jacket laws vary by state — and in states without such laws, Coast Guard regulations requiring children 13 and under to wear approved, well-fitting life jackets on a moving boat — apply. Some states may also require adults on a moving boat to have their own approved life jacket on board.

How do you know your life jacket is safe to use?

Choosing the right life jacket is important in order to stay safe on the water, whether you’re borrowing one at a facility or purchasing one online. Luckily, there are a few quick and easy rules to follow for this.

“It is important to select a U.S. Coast Guard-approved life jacket and ensure that the life jacket is in good working condition,” says Michelle Sterling, senior program manager at Safe Kids Worldwide. Simply look for the USCG approval label on the life jacket and make sure it’s still legible.

Sterling recommends checking to make sure that all hardware and straps are in good shape and still working. She also recommends people check for rips or tears, as well as leaks, mildew and even oil saturation in the fabric.

Katchmarchi and Sterling both warn that life jackets should not be worn if they are damaged in any way. That applies to life jackets that are ripped, torn, have faded material or punctures and so on.

“If it looks like it's 20 years old, the material's barely holding together and the buckle is on its last leg, I wouldn't wear it. I would demand a new life jacket,” says Katchmarchi.

How to make sure you've got the right fit

Experts agree that when it comes to life jackets, size and proper fit are of the utmost importance. The U.S. Coast Guard puts life jackets into four weight categories: adult (anyone over 88 lbs.), youth (between 55 lbs. and 88 lbs.), child (between 33 lbs. and 55 lbs.) and infant (under 33 lbs.).

“Life jackets are weight and body size dependent,” says Katchmarchi. He warns parents especially against potentially putting their child in the wrong size life jacket.

“If a child falls in the water and the device is too big for them, they will fall out of the device,” he says. “If they weigh 65 pounds and the device [they’re wearing] is weighted for 50 pounds, that device is not going to provide enough buoyancy for the child.”

Sterling advises all life jacket users to first check the label to make sure they’ve got the correct size. “While wearing the life jacket, make sure that the straps are buckled to ensure the life jacket is being worn properly,” she adds.

The life jacket should feel a bit snug, while still allowing for comfort and movement. One common test experts recommend is having someone pull the shoulder straps up a bit to make sure it doesn’t slip up over your face or head (or hits the ears or chin on children). Once you’ve checked all those boxes, you’re good to go on the water, knowing that your life jacket will protect you in the event of an emergency.