If you are in the ocean when a storm approaches, it's always best to get out of the water as soon as you hear thunder. It's even better if you then vacate the beach to safety indoors as well. Lightning can strike anywhere within the hearing range of thunder, and the bolt can travel in a straight line in any direction. I learned this the first summer after moving to Florida. Our family was walking along Ormond Beach on a sunny day. The sky was blue and the ocean was calm but what we didn't know was that a thunderstorm was coming our way. In Florida, it's not unusual to hear thunder at any time since the storms come up quickly, but what we saw that day has always been remembered. A man was walking ahead of us down the beach. He was probably one hundred years away when out of the sky came a massive lightning bolt that killed him instantly. It took place about fifteen minutes before we saw the clouds roll in and the sun was shining brightly and then he was dead.
When lightning hits salt water, the charge can travel outward in a radius of about twenty feet. It can be felt much farther away but not in a life threatening way. Additionally, there is danger from the sound of the strike which can blow out eardrums within thirty feet of the direct strike. Don't play around with lightning. Since most of us know not to stand under a tree which can act as a lightning rod, we don't want to be standing or walking on a flat and largely unoccupied beach during a storm either. And in the water we are literally playing with the likelihood of fire reining down on us at any time during a thunderstorm.
So, play it safe around lightning. When you know it's coming your way, get out of the water and off of the beach. Go back to your lodging and play cards or use the time to get a bite to eat instead. After all, who wants to come to an end on vacation at a beautiful beach because of stupidity. Don't be stupid, choose a safe path and live for another day. Otherwise, you might as well be standing in the middle of a runway that will soon be host to an arriving 737. Just be safe first and then have fun.