Most of us know that feeling of calm we get when we are on, in or just near the water.
"This is what you want if you're in the midst of a stressful week," said Wallace J. Nichols, a marine biologist and conservationist who lives near the central coast of California. "You just want to hit that big blue reset button and get out here."
Nichols spent much of his professional life trying to protect endangered sea turtles. Now he's exploring the scientific reasons for why humans have such a deep connection with the deep blue.
"There are all these cognitive and emotional benefits that we derive every time we spend time by water, in water or under water," Nichols said.
The marine biologist dubbed it our "blue mind," the mildly meditative state our brains enter when exposed to water.
Initially, Nichols was apprehensive that people would dismiss him as a California beach-lover, but he attests that his thesis is scientifically backed.
"Once you get into it, you realize that it's chemistry, it's biology, it's physiology. It's deeply personal but it's also strong science," Nichols said.
The science is still evolving, but Nichol's work is getting plenty of attention. He began hosting "blue mind" seminars that are attracting neurologists and psychologists from around the world.
Brain imagining indicates that proximity to water floods the brain with feel-good hormones such as dopamine and oxytocin. Levels of the stress hormone cortisol actually drop. Scientists have also discovered that the brain prefers the color blue above all others and water increases our ability to focus.
"Our response to water is deep," Nichols said. "It's human, it's about life and it's about survival."
In fact, our bodies consist of about 60 percent water and our brains, a whopping 75 percent.
"So when you see water, when you hear water, it triggers a response in your brain that you're in the right place," Nichols said.
From rafting to kayaking to surfing, water therapy is increasingly being used to treat a variety of ailments, including wounded veterans suffering from post-traumatic stress and depression.
"I think connecting public health to a healthy ocean is critical," Nichols said. "It helps you relax, just literally sucks the stress out of your body and out of your mind."
So the next time you gaze into that blue horizon, you'll know that feeling you get really is all in your head.