Can Scuba Divers Pass Gas Underwater? Busting the Myth

There's a persistent myth in diving circles that once you hit 33 feet underwater, your body somehow loses the ability to pass gas. It sounds scientific enough—something about pressure and physics—but it's completely false. Divers can absolutely fart at any depth, including 33 feet and far below. What does change is how it feels.

The confusion stems from a real phenomenon, just misunderstood. At depth, increased pressure affects all gases in your body, including intestinal gas. But "affects" doesn't mean "prevents."

The Physics of Underwater Flatulence

Boyle's Law is the key player here: as pressure increases, gas volume decreases. For every 33 feet you descend, the pressure increases by one atmosphere. So at 33 feet, you're experiencing twice the surface pressure.

This means the gas bubbles in your intestines compress. At 100 feet deep, they're roughly a quarter of their surface size. When those bubbles shrink, the urge to fart diminishes dramatically—sometimes disappearing entirely. Your body doesn't feel the pressure building because, well, the gas isn't taking up much space.

But here's the thing: just because you don't feel like you need to fart doesn't mean you can't. The gas is still there, just compressed. If you tried, it would still come out.

What Goes Down Must Come Up

The real fun begins during ascent. As you swim toward the surface and pressure decreases, those compressed gas bubbles expand again. That tiny, unnoticeable pocket of gas at 100 feet? By the time you're at 30 feet, it's screaming for attention.

Many divers report needing to fart more urgently during ascent than they ever did on land. It's not that they're producing more gas—it's that the gas they already had is now taking up significantly more space. Physics doesn't care about your dignity.

The Practical Side

From a safety standpoint, farting while diving is perfectly safe. In fact, holding it in is potentially more problematic than letting it go. While rare, trapped expanding gas during ascent can cause discomfort and theoretically contribute to issues.

The bubbles rise faster than you do, dissipating harmlessly into the water. Your dive buddy might notice, but they're probably too busy managing their own bodily functions to judge.

Why the Myth Persists

The 33-foot threshold in the myth isn't random—it's the depth where you've doubled surface pressure, making the gas compression effect quite noticeable. New divers at this depth often realize, "Hey, I don't feel gassy anymore!" and conclude they can't fart rather than they simply don't need to.

Add in the natural human tendency to turn bathroom humor into "science facts," and you've got a myth that spreads faster than bubbles rising through seawater. But now you know better: your digestive system works at any depth, even if it doesn't always feel like it.