I’ll never forget the morning that changed how I see snorkeling. I was floating off a calm Hawaiian beach, watching a school of butterflyfish drift past, when I noticed a woman nearby. She was face-down in the water, completely still. No fins kicking. No bubbles. No arm waving. Just a quiet, terrifying stillness.

A lifeguard reached her in seconds. She was unconscious, not struggling. She survived, but here’s what haunted me afterward: nobody around her—including me—had seen any sign of trouble. Her body had already signaled an emergency, but none of us knew how to read it.

That day sent me deep into the research on snorkeling safety, especially the work coming out of Hawai‘i’s Snorkel Safety Study. What I found flipped everything I thought I knew about drowning upside down. And it changed how I prepare for every single swim.

The Drowning We’re Taught to Watch For Isn’t the One That’s Killing Snorkelers

If I asked you to picture a drowning, you’d probably imagine splashing, gasping, arms flailing. That’s aspiration drowning—water filling the lungs, triggering a desperate fight. It’s dramatic. It’s visible. And yes, it happens.

But the data from Hawai‘i paints a different picture. Between 2014 and 2023, snorkeling claimed more visitor lives than swimming, surfing, and scuba diving combined. And when researchers dug into the mechanisms behind those deaths, they found something surprising: most were likely not aspiration events at all.

They were caused by something called Snorkel-Induced Rapid Onset Pulmonary Edema—or SI-ROPE. The snorkel’s resistance creates a vacuum in your chest, pulling fluid from your blood vessels into your lungs. You don’t swallow water. Your own body floods your lungs from the inside. There’s no struggle. No splashing. Just a quiet, rapid shutdown.

Survivors describe the sequence the same way: sudden shortness of breath, overwhelming fatigue, a feeling of doom, then darkness. No flailing, no cry for help. The emergency happens silently, and by the time anyone notices, it’s almost too late.

Your Body Sends Three Signals Before You Ever Raise an Arm

Here’s what I now tell every friend before we get in the water: the most important emergency signal isn’t a wave or a whistle. It’s something you feel in your own body. Learn to listen for it.

Signal One: Shortness of breath that doesn’t match what you’re doing. You’re floating. Maybe kicking gently. But each breath through your snorkel feels like work. This isn’t normal exertion. This is your body warning you that negative pressure is building in your chest, or fluid is already accumulating in your lungs.

Signal Two: Fatigue that feels wrong. You know what tired feels like after a good swim. This is different. Your legs turn to lead after two minutes. Your arms feel heavy. Survivors describe it as a sudden, unnatural weakness that doesn’t go away with rest.

Signal Three: A creeping sense of unease or doom. This isn’t panic—it’s your brain responding to dropping oxygen levels. Many survivors say they felt something was deeply wrong before they could name it.

If you experience any of these, act immediately:

1. Remove your snorkel and mask.
2. Roll onto your back to keep your airway clear.
3. Breathe freely through your mouth.
4. Signal calmly for help if needed.
5. Get out of the water as quickly as you can.

The Snorkel Safety Study’s message is blunt: shortness of breath is a danger sign. Don’t wait to see if it passes. Don’t try to tough it out. Get out.

What to Look For in a Buddy—Because It’s Not What You Expect

“Swim with a buddy” is good advice, but it only works if your buddy knows what to watch for. Here’s what the research says to keep an eye on:

• The drift. A snorkeler in trouble often loses awareness and starts drifting with the current. Check your buddy’s position every 30 seconds.
• The quiet float. If someone is face-down and still, don’t assume they’re admiring the coral. Approach immediately.
• The mask removal. If your buddy takes off their mask at the surface without a clear reason, ask them directly: “Are you okay?”
• The frozen stare. Panic doesn’t always look like flailing. Sometimes it looks like a wide-eyed person who can’t move or respond.

Also keep this in mind: almost all near-drowning events in the study happened where the person couldn’t touch the bottom. If you’re in deep water, stay closer to your buddy than you think you need to.

Your Gear Matters More Than You Realize

I want to be honest here, because I work with Seaview 180, and I believe in saying what’s true. Our masks are designed for surface snorkeling, and we engineer them to support comfortable breathing and reduce CO₂ buildup. But no piece of equipment removes the inherent risks of being in the water.

The Snorkel Safety Study tested 50 different snorkel devices and found something striking: resistance varies wildly between designs, and you can’t judge it by looking at the mask. A device that looks low-resistance might require serious effort to inhale through, especially when you’re breathing harder from mild exertion. Among near-drowning survivors in the study, 38% were using a full-face mask—and 90% of those felt the mask contributed to their trouble.

That’s why I always do this before heading into deep water:

• Test any new mask in waist-deep water first.
• Breathe through it while resting, then while swimming gently.
• If it feels resistive or uncomfortable, try a different design.
• Make sure the fit is snug but not tight—a poor seal can increase breathing effort.

The study’s advice? Inhale large volumes of air through the snorkel before buying it. Get a feel for the resistance. And always try your equipment in a safe environment first.

One Surprising Factor: Recent Air Travel

Here’s a detail from the research that most people don’t know. Prolonged air travel exposes you to mild hypoxia—lower oxygen levels—for hours at a time. That might subtly weaken the membrane in your lungs that keeps fluid out. If you hop off a long flight and head straight into the ocean, your lungs may be more vulnerable to SI-ROPE for the next couple of days.

The study couldn’t prove a direct link, but the physiology is solid. The safety recommendation is clear: consider waiting two to three days after long-distance air travel before snorkeling.

I know that’s hard when you’re on vacation and every day feels precious. But I’ve heard too many stories of people who wished they’d waited. Give your body time to recover. The reef will still be there.

Changing the Culture: It’s Okay to Stop

What I want most is to help change how we talk about snorkeling safety. So many survivor accounts describe pushing through discomfort because they didn’t want to seem weak or inexperienced. They kept going when their body was screaming at them to stop. Some nearly died because of it.

I now tell every person I snorkel with, before we even get in the water: “If you feel short of breath, if you feel more tired than you expect, if something just feels wrong—tell me. Take off your mask. Float on your back. We’ll head in. There’s no shame in calling it early.”

That conversation matters. It sets the expectation that safety comes before pride. And it creates a culture where recognizing an emergency signal—in yourself or someone else—is seen as smart, not embarrassing.

What I’ve Changed in My Own Routine

After reading the study, talking to survivors, and spending more time thinking about the physics of breathing through a snorkel, I’ve adopted a few habits that I hope you’ll consider too:

• I always test new gear in shallow water before going deeper.
• I check in with my buddy every couple of minutes—eye contact, thumbs-up.
• I pay attention to how I feel, not just what I see.
• After a long flight, I give myself at least a day before getting in the water.
• I’ve stopped using any snorkel that feels resistive, even if it looks fine.

Snorkeling is one of the most beautiful ways to connect with the ocean. I want all of us to keep doing it for a long, long time. That starts with understanding that the most important emergency signal isn’t a wave or a whistle—it’s the quiet message your body sends you. Learn to listen to it. Trust it. Act on it.

That’s the most powerful safety tool you’ll ever own.