Humans have a lot of self-calming rituals built around water. We treat ourselves to long, hot baths. We buy hot tubs and visit flotation tanks and use special showerheads that are designed to feel like rain. We install water features so we can listen to cascading fountains inside our homes. And if we don’t have the real thing, we might turn to an app so that the sound of ocean waves or a running brook can lull us to sleep.

Even though we’ve been soaking in hot springs and communal baths since ancient times, we know surprisingly little about why we feel this way about water. Scholars have theorized that water calms us because we evolved from the sea; because we lived in amniotic fluid; because finding a body of water in a dry land meant we were going to survive. Those are all possibilities, according to experts, though the theories are difficult to test.

What we do know for certain is that water alters our consciousness—and experts believe we can leverage this phenomenon. It’s known among researchers as the “Blue Mind.”

Research shows that looking at water, or even just pictures of it, can lower blood pressure and improve mental health. Scholars have begun to study “blue spaces”—oceans, lakes, ponds, rivers—as an outgrowth of research on how people respond to “green spaces.” This is an urban planning initiative that has established that nature improves mental and physical health and society as a whole.

One of the more testable theories about why water affects us the way it does is Attention Restoration Theory (ART). For many of us, life requires endless focus. We multitask while working, while commuting, while managing our home lives. Looking at nature, and particularly water, doesn’t demand focus. Your senses and mind can wander. You can sit and listen to the various sounds it makes as it ripples or rushes or foams or swirls in endless patterns, playing with light and stones and sand. It’s profoundly restorative, according to ART.

“It feeds into improved relaxation, mindfulness, sensory engagement, and almost that fascination that we often get with water,” says Craig McDougall, PhD, a research fellow at the University of Exeter in the United Kingdom who writes about the wellness benefits of blue spaces. “That feeling watching waves crashing; you almost go into a trance… when you spend time around water bodies or different natural environments, your brain is able to restore attention, to recharge.”

It's our attraction to water that helps our brains to rest. “Fascination is almost like a prerequisite for this attention restoration,” McDougall says. “So it's almost like this idea of going into a trance or being in awe of the environment where you're fascinated, you're fixated on it.”

Kevin Conrad, MD—a primary care provider who previously studied the role of water on life— notes in an email that, “The rhythmic sounds of water allow us to effortlessly enter a meditative state, similar to music. It significantly improves mental health by lowering cortisol (stress hormone) while increasing dopamine, serotonin, and oxytocin. Creativity is improved.”

In a 2023 study, researchers asked a group of older adults about their experiences with green and blue spaces. The participants said they found blue spaces important for spiritual restoration and mental well-being.

Some studies have been done on how floating in water impacts the brain. Floatation‐Reduced Environmental Stimulation Therapy (REST), for example, “reduces stimulation of the human nervous system by minimizing sensory signals from visual, auditory, olfactory, gustatory, thermal, tactile, vestibular, gravitational, and proprioceptive channels,” according to a 2021 paper.

In other words, when you’re floating in water, you’re not connected to all the things that make your world familiar—like gravity and friction—so you can let go. Flotation calms the parts of your brain considered responsible for self-referential thought. And that can reduce depression and anxiety.

Part of the problem with researching the impacts of blue spaces and water exposure is that much of it is based on reported experience, which varies a lot. One 2022 study showed that people who grew up around blue spaces are much more likely to seek out and take solace in blue spaces as adults. They’re also more likely to be healthy as adults. Another 2022 study based in the United Kingdom noted that just living near an ocean or having a sea view is associated with improved mental well-being, reduced mental distress, and reduced antidepressant medication usage. Researchers also know that “blue zones”—or areas of the world with high populations of healthy, long-lived people—happen to fall in coastal areas, like Okinawa, Japan, though diet and social factors also likely play a role.

However, this doesn’t mean that oceans are the key to good health for everyone; other people are hydrophobic—or averse to water. After all, water is connected with many dangers like drowning, floods, and disease. Some people live in areas where water either isn’t accessible or maintained so it may be full of pollution or emits odors.

It’s also difficult to research the effect of water because researchers can’t see what is happening in the brain when someone is around it—in other words, it’s hard to get an MRI machine plugged in next to a seashore. The closest most researchers have come is to track brain activity when someone looks at pictures or listens to recordings of ocean waves or running brooks.

For example, a 2017 study substituted pictures of landscapes (water, forest, mountain, and urban) for the real thing so they could use functional magnetic resonance imaging (fMRI) to see how people’s brains responded. Sure enough, when participants viewed the water environment after experiencing stress, their electromyography rate—or the measure of electrical activity produced by skeletal muscles—decreased and respiratory rate slowed, indicating more relaxation and restorative benefits, respectively.

Likewise, an older study from 1984 tested whether looking at an aquarium could help patients who were about to have oral surgery remain more relaxed. They tested the aquarium against other interventions—including hypnosis—and the aquarium won. In addition to dentist office fish tanks, studies suggest other artificial bodies of water could induce similar benefits, too.

Richard G. Coss, PhD, emeritus professor of psychology at the University of California Davis, led a University of California Davis study involving a small, somewhat ugly swimming pool. Participants spent two minutes looking at a concrete pool, then moved to a tree in a parking lot, and finally to a street sign. They wore devices that measured heart rate and blood pressure. Even though the pool was decidedly lacking in ambience, the participants’ blood pressure was measurably lower while looking at it versus the other objects. In terms of heart rate, the pool and the tree were both better at reducing heart rate than the street sign.

Conrad came to a similar conclusion to Coss, saying that it’s possible to experience the benefits of water even without a natural body around.

“I used to think that the benefits of the ‘Blue Mind’ could only be achieved by being around wild water—rivers, lakes, oceans—but patients have told me that they have come to find out they like any water,” Conrad says. “The research bears this out as well. This includes taking baths, having an aquarium, being around fountains, and even drinking water can have a therapeutic calming effect.”

However, this isn’t unrefuted. McDougall says that they’re no substitute for natural bodies of water. As more and more research proves that water is good for mental and physical health, he argues it’s time to incorporate that into urban planning and to set aside investment money to make sure people who are both rich and poor, urban and rural, have access to this natural wellspring of physical and mental health.

So next time you’re wading through crashing waves—or perhaps simply turning on your shower—just know that your mind might be changing for the better.