“Don’t fight it,” says Alexus Kwachka, a commercial fisherman from Kodiak, Alaska, who still gets seasick even after 30 years of traveling between the Bering Strait and the Gulf of Alaska. “Go to the rail and puke as soon as you can.” Do so over the leeward side of the boat, facing downwind. Don’t feel ashamed. For Kwachka, it helps to keep the mood light. He tells the crew he’s going to “look for Buicks,” vomits over the side and then sneezes. “That seems to reset things,” he says.

Scientists don’t entirely understand how motion sickness is triggered or why humans and other animals (fish included) experience it. They do know it stems in part from sensory conflict, like discord between visual input to the brain and signals sent from the parts of the inner ear responsible for balance. Some research suggests that facing forward and focusing on a distant point on the horizon can minimize symptoms. Because the placebo effect on seasickness is particularly strong, the prevention measures you believe in are more potent. Kwachka has seen people try everything from chewing ginger root to wearing special bracelets. If you do feel ill, fresh air helps. Drugs, too, but the sedative effects of most anti-motion pharmaceuticals are incompatible with making your livelihood at sea. The most effective treatment is exposure; militaries in many countries run weekslong motion-sickness desensitization programs.

Generally, the more lurching and vertical the motion, the worse you’ll feel. On a few occasions, though, Kwachka has been out in truly perilous storms with 40- and 50-foot ocean swells. In those conditions, adrenaline is likely to override everything else. “If your life is in jeopardy, seasickness is the last thing you’re focusing on,” he says. As is true of most things, your psychological state matters: While nearly every human is susceptible to motion sickness, people prone to anxiety and neuroticism are more so. Discussing your symptoms may worsen them, while calm breathing can have the opposite effect. Try to relax. “As a species we want to be in control of just about everything,” Kwachka says. “On the water you need to let go.”