Stay calm, if you can. Panic burns oxygen. The first wave is often the worst. As it passes, start swimming for light, but conserve energy. The ocean will usually spit you up for a quick gasp before the next one hits. Use that split second to inhale deeply and get your bearings. Trust that the set will pass. Fighting against the entire ocean’s energy is exhausting and futile; sometimes you just have to let it have its way with you for a moment.