In freshwater or salt, snorkeling is a gateway to beauty, adventure and a new appreciation of the underwater world.

For such rich rewards, the sport doesn’t ask for much in return. Snorkel, mask and fins are relatively cheap to rent or buy. Snorkeling requires only a little training. In many places it doesn’t even require a boat: Coral reefs and other interesting structures lie close to shore. Compared with scuba diving, snorkeling is a cinch.

“It’s a lot easier to get into,” says Cate Kelliher, a dive instructor for Quiescence Diving Services in Key Largo, Florida. “You can practice very easily off shore.”

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But while snorkeling is economical and easy, that doesn’t mean it’s entirely risk free. One Australian study — which reinforced how safe the sport is overall —  found that some people got in trouble because they were weak swimmers or had an underlying heart condition that resulted in a heart attack. According to the report, most victims were either snorkeling alone “or had lost contact with a buddy.”

Here’s how to keep you and your family safe on your next snorkeling adventure.

Check with your doctor first. If you’re on the older side or have an underlying health condition, ask your doctor how to best prepare for snorkeling.

Snorkel with a companion. A friend, especially one who is a stronger swimmer, can bolster your confidence and provide aid if you get tired or swallow water.

Don’t snorkel if you can’t swim well. “Everybody who snorkels needs to be comfortable in the water,” says Kelliher. While snorkeling doesn’t take a lot of skill or athleticism, it does require that you can stroke along with your head underwater. You must be able to empty your mask or clear your snorkel without panicking. “You need to be aware that at some point you’re going to get water in your mask,” says Kelliher.

Do some practice runs. If you’ve never snorkeled before, practice in shallow water so you can stand up if you get tired, inhale some water or panic. Likewise, try out unfamiliar equipment in waist-deep water before venturing deeper.

Start out close to shore, if possible. Depending on the location, some great snorkeling can be found within a few yards from shore. If you get tired, just a few strokes will get you back to shallow water.

Wear a vest. If you have any reservations about your endurance in the water, wear an inflatable snorkeling vest. Blowing a few breaths of air into the valve will provide enough buoyancy for you to rest. And the vest’s bright color will make you visible to boaters.

Be tuned in. Practice what Kelliher calls “aquatic awareness.” That’s especially important if you’re far from shore. “You need to know where you are in relationship to your boat, the reef and other boats,” she says. Being tuned in includes being aware of currents that may be carrying you away from your boat or larger-than-expected waves that may deposit you bodily on a reef or rocks. Experienced snorkelers know not to snorkel too close to reefs so they won't get unexpectedly pushed into one — and either harm the coral or be harmed by it.

Don’t overdo it. Learn to relax and move with minimal effort. Don’t swim and dive to the point of exhaustion. Keep enough reserves so you can deal with a distraction (such as swallowing water) and still have energy enough to get back to shore or the boat. 

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Don't pull stupid tricks. No matter how experienced you are, don't try the trick some snorkelers use of repeatedly hyperventilating so they can stay underwater longer. That's a recipe for hypoxia (oxygen-deprivation in the body) and even a shallow water blackout. These blackouts usually occur at a depth of 15 feet, when the oxygen-starved lungs start actively absorbing oxygen from the blood. They can be fatal. They can also occur if you just hold your breath way too long.

Dress for the conditions. If the water is cold (even if it’s just in the 70s), wear a wetsuit for warmth. On sunny days, especially in the tropics, wear sun protection. A heavy layer of sunscreen dissolves in water and damages coral. A better choice is a tight-fitting sun-blocking top such as a rash guard or swim shirt.

With a few precautions, you’ll be able to swim safely with those small bright-colored fishes you thought you’d only see in the aquarium.

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Greg Breining is a Minnesota-based journalist who writes about science, travel and nature for national and regional magazines, including Audubon and National Geographic Traveler. His books about the natural world include Wild Shore and Paddle North.