On July 4, 1952, renowned swimmer Florence Chadwick entered the grey and forbidding waters of the North Pacific off the island of Catalina.

Florence was already the first woman to swim the English Channel twice. Now she was determined to become the first woman to cross the Catalina Channel to the California coast 26 miles away.

She was well trained for long and difficult hours in the open ocean, and for swimming in fast, insidious and unpredictable currents.

Florence was well aware that the area was notorious for great white sharks that thrived on seals in the numbingly cold water. Psychologically and physically, she was prepared. She was fit, focused and unstoppable except there was one crucial thing she hadn’t planned for.

As she swam into the wild and open sea, dense and viscous fog surrounded her in a thick wall. She couldn’t see anything around her, even the accompanying boat with her mother and coach.

She could only hear their loud yells and the booming sound of rifle shots, which the crew fired into the air to scare away the sharks. She swam slowly and consistently, hour after hour, gritting her teeth.

She struggled with fatigue, cold, exhaustion and the terror of being pulled below the dark water in the jaws of death. She put all of this in a box in her mind and closed it. She forced the voice screaming inside her to be silent and focused on her strokes — first one, then another, then another.

She could see nothing but emptiness below her and nothing but the impenetrable fog above. It was dead calm, just the relentless ocean swell, distant voices in the grey ether and the reverberations of gunshots. She swam five hours, then ten, then fifteen. She discovered loneliness; not the kind where you miss everyone, the loneliness of being a single soul in a vast and hostile world.

After 15 hours and 55 minutes, she gave up. She was dragged into the boat sobbing, frozen to the core of her bones. They wrapped her in blankets as she clutched hot-water bottles. Slowly, she found herself once more.

She was lying in the swaying boat, violently trembling and staring into the grey mist. The fog broke apart, great rents appearing in the swirling fabric. Something was out there. She strained to make it out, and in a rush of disbelief she saw it appear as in a dream: the shore.

It was less than a mile from her. If she had continued to swim, in only twenty minutes, she would have reached the coast.

Later, surrounded by journalists, Florence said: “All I could see was the fog. … I think if I could have seen the shore, I would have made it.”

Two months later, she crossed the same channel in an astonishing 13 hours, breaking the men’s record by two full hours. There was also a dense fog on that day. Only this time, she kept a bright and vivid mental image of this shore in her mind. She knew exactly where she was swimming without even seeing it.

We all have times when we don’t have a clear purpose, when we don’t know where to go and what direction to take.

How often, wandering in the mist of doubt, do we lose ourselves in the fog of uncertainty?

We do not understand that what we are looking for might be so close, literally within reach, because we do not see it. We take a step at random, then another one and then, doubting ourselves, we turn the opposite way.

What we need at this time of doubt and hesitation is to clearly see the final destination. The shore, the lighthouse, the pier, the light in the windows of the house where friends expect us. Then we gain new strength and break through. When we hold our goal in our mind’s eye and never waver, we will reach it. Florence did.

•Nina London is a certified wellness and weight-management coach. Her mission is to support and inspire mature women to make positive changes in their body and mind. Share your inspirational stories with her at www.ninalondon.com