Choosing a Life Preserver
Bryant Stamford, PhDTHE PHYSICIAN AND SPORTSMEDICINE - VOL 24 - NO. 5 - MAY 96
A life preserver, also called a personal flotation device (PFD), is a vital sports accessory. According to the US Coast Guard, three of four people who have drowned while boating could have been saved by wearing a PFD.
The main function of a PFD, of course, is to keep a person afloat, or buoyant-even with heavy clothes and gear. Its buoyancy also helps a stranded person save energy, because without a PFD a swimmer has to continually work to stay afloat. Some types also help keep a victim's face out of the water.
A PFD's buoyancy is the amount of weight it can keep afloat. High buoyancy is over 20 pounds. This may sound low, but water provides lift, so the average adult needs only 7 to 12 pounds of buoyancy.
Five Approved Types
But higher buoyancy means a bulkier PFD, which may interfere with activity or be unnecessary in certain situations. Therefore, the US Coast Guard has approved five types (figure 1).
Type 1 is meant for offshore use-boating in a large body of water like an ocean. Accidents at sea may require prolonged flotation in rough water, and some victims may lose consciousness, which requires that the PFD hold the wearer face up. To fit the bill, a bulky PFD is required that provides a minimum adult buoyancy of 22 pounds.
Because of the bulk, a type 1 PFD may be uncomfortable when worn out of the water. It's also not fashionable-which may explain its absence at cocktail parties. Fashion is not a major problem, though, because a type 1 PFD is usually used only in an emergency.
Type 2 is a less bulky version of the type 1 PFD and is meant for near-shore use. This typically means relatively calm, inland water and potentially short immersion time. A type 2 PFD has less buoyancy (15.5-pound minimum), and is less effective at turning a person face up. The type 2, though, is more comfortable out of the water but still may be too bulky for continuous wear.
Type 3 is called a flotation aid. It is more streamlined than types 1 and 2, but less effective. Designed for when a fast rescue is likely, it has a buoyancy of at least 15.5 pounds. The sleek fit offers greater comfort and mobility. Its most common styles are the classic vest and the flotation coat.
Type 4 is a throwable device, commonly called a lifesaver. Besides the familiar doughnut shape, it also comes in a horseshoe and a square cushion. A type 4 is considered to be only a backup measure and takes practice to throw well.
For it to be effective, help must be near. Once the device is thrown, the victim has to be able to get to it, and therefore must be conscious and somewhat of a swimmer. Also, a throwable device is difficult to use in currents or high waves. Cushions have a higher buoyancy (18 pounds) than do rings (16.5 pounds).
Type 5 is designed for specific purposes like boardsailing or whitewater activities. A type 5 must be worn only for its designated activity.
Some type 5 PFDs are inflatable and offer great buoyancy when inflated (22 pounds) plus less bulk when deflated. Continuous wear is comfortable when the PFD is not inflated. Without inflation, though, buoyancy is markedly reduced (7.5 pounds). Also, the inflation chamber must be checked regularly.
Fit to Be Tried
A critical factor in selecting a PFD is fit. The law requires that each PFD be the appropriate size for each person on board. Once fit is ensured, put your name on the PFD. Never have a PFD altered to make it fit better. Trimming and tucking may interfere with its intended purpose.
Adult. Your PFD should hug snugly without confining or riding up. A PFD that rides up in the water can plunge your face beneath the surface. Type 2 and 3 PFDs should fit comfortably enough for prolonged wear. The type 3 should allow full freedom of movement.
Child. A child will likely not be aware of a poor fit, so adults must closely supervise. Look for a PFD appropriate for the child's weight. Even a child's PFD, though, can ride up dangerously high.
Have the child put on the PFD, then lift him or her by the top of the PFD-or simply pull up on the shoulders. It should not ride up over the chin and ears. A crotch strap may be needed to help keep the PFD in place.
Tried and Tested
To truly find out how well a new PFD performs, there's no substitute for a "road test"—try it in the water. Also test a tried-and-true PFD periodically, at least once a year.
Enter shallow water, bend your knees, relax, put your head back, and keep your hands at your sides. Don't tread water or touch the bottom. If your chin is above water and you can breathe easily, your PFD is working well. (If a new PFD fails this test, return it!) If you might be using your PFD in rough or cold conditions, add heavy clothing and gear.
Test for wear and tear annually by checking for holes, rips, mildew, and waterlogging. If your PFD uses the naturally buoyant fiber called kapok, squeeze the vest for air leaks. If it leaks, throw it away. Similarly dispose of any PFD that is torn or waterlogged. If you have an inflatable PFD, make sure the inflation chamber works properly.
When buying a PFD, also look for a quick-drying and durable nylon shell and a rustproof plastic zipper. To get long-term wear, avoid plastic trim. It cracks and flakes.
Prices for PFDs vary, but if you seek sufficient quality, expect to pay at least $50 for a child's PFD and $65 for an adult's. Safety is not the place to scrimp on cost.
Remember: This information is not intended as a substitute for medical treatment. If you have questions about health or safety, consult a physician.
Dr Stamford is director of the Health Promotion and Wellness Center and professor of exercise physiology in the School of Education at the University of Louisville, Kentucky. He is also an editorial board member of The Physician and Sportsmedicine.