In the end, neither sharks nor exhaustion ended Ben Lecomte’s mission to swim 5,000 miles across the Pacific Ocean.

A damaged mainsail on the 67-foot yacht Discover, aboard which the Austin explorer slept during his planned swim from Japan to San Francisco, brought the expedition to a halt after about 1,700 miles.

Lecomte, 51, stepped into the water in Choshi, Japan, on June 5. Wearing a wetsuit, snorkel and fins, he navigated crashing waves, the occasional shark, swirls of colorful fish and unfathomably deep water before storms began pummeling his team in early November. The support yacht’s heavy-duty sail and its rigging couldn’t hold up to the wind and waves, and the crew broke nine pencil-size needles repairing rips over and over.

“In the end, we couldn’t sustain it,” Lecomte said recently at a coffee shop in Round Rock. “I was willing to push through and not stop, but there were nine other people with me, and I couldn’t compromise their safety.”

In other words, his equipment broke before he did.

Lecomte called off the expedition Nov. 11, pointed his limping support boat toward Hawaii, a three-week sail away, and flew back to Texas in late December, foiled but not defeated.

“I was very disappointed, because I wasn’t the one failing even though I was the weakest link,” he says. He never reached his personal limit, something he longed to discover. “I never hit the wall; I never felt I couldn’t make it because it was too difficult physically or mentally.”

Lecomte was using his swim to draw attention to the problem of plastic pollution in the world’s oceans. Walking on the beach or swimming in the ocean as a child, he saw sand and clear water, not discarded plastic. Swimming hundreds of miles from the nearest shore in the Pacific, though, he encountered fishing nets, soda bottles, shampoo containers and tiny, confetti-size bits of pulverized plastic.

Lecomte, who is an architect and builder by profession, collected water and garbage samples during the five months he swam, and he plans to return next spring to continue his journey.

“It was never a one-time deal for me, even if I had completed the swim,” he says. “I wasn’t going to say, ‘I’m finished.’”

He had spent seven years preparing for the trip and says his biggest fear when he set out was not finishing.

“I look at it a different way now,” he says. “It’s not something I had control over, so I can’t be upset. All I can do is look at what didn’t go right and try to correct it and keep on focusing on the mission — to get people's attention on plastic and the problem we have.”

As a child growing up near Paris, Lecomte prepared early for a life as a downhill ski racer. A doctor diagnosed him with a pinched disc in his back when he was 14, ending those dreams, but suggested swimming. Instead of joining a team and training in a pool, though, Lecomte headed to rivers, lakes and oceans.

When he learned about a man who was rowing across the Atlantic, the seed was planted. He’d try the same thing, only he’d swim it.

“I never wanted to replicate something that had been done before, like (swimming the) English Channel,” he says. “It wasn’t my thing.”

In 1998, he completed a “drift swim” across the Atlantic Ocean, swimming by day and sleeping aboard a drifting boat at night, covering about 3,500 miles in 73 days.

For the Pacific swim, he marked the GPS coordinates of each day’s finishing point and picked up at the same location the following day. That way, he would cover every inch of the nearly 5,000-mile endeavor, and followers could monitor his progress via an online tracker.

Also, this time he held onto a bigger purpose. “I wanted to do something to bring the attention to plastic,” he says.

The United Nations Environment Programme estimates that more than 8 million tons of plastic waste — the equivalent of a dump truck load every minute — trickles into the oceans each year.

Lecomte prepared by exercising four or five hours a day five or six days a week. He swam some but mixed it with bicycling and running so he didn’t burn out before he even began. He didn’t concern himself with his speed, describing University of Texas swimmers as the Formula One vehicles of the swimming world and himself as a beat-up old pickup truck.

“It’s more an adventure than an athletic feat,” he says.

During his swim, Lecomte covered about 20 miles a day, depending on currents, in water that ranged in temperature from the low 70s to the low 80s. To stay on course, he followed a line attached to a dinghy or kayak that led the way.

Eight hours of swimming burns an estimated 8,000 calories, so Lecomte paused every hour or two to eat warm soup and a few slices of fruit and nut bread baked onboard by the yacht’s skipper.

“That was good because it was solid food but I was able to digest it easily,” he says.

At the end of each day, he ate carbohydrate-heavy meals like rice, pasta, quinoa or couscous, occasionally fish caught by the crew, and a protein shake. Another diet staple? Canned Spam.

“When you’re hungry, it’s not that bad,” he says.

The most challenging part of the swim was mental. To get through eight hours a day with his face in the water, he pre-planned what he would think about, hour by hour. He started by reflecting on the prior day’s swim, then brainstormed about his mission to draw attention to plastic pollution and how his blogs and social media posts could help. He also imagined experiences he had had with his wife and two children — and some that he hopes to have — in minute-by-minute detail. In essence, he daydreamed his way through hours of swimming in the ocean, dissociating his mind from his body.

“Sometimes you pass your exit; it’s exactly the same thing,” he says. “You’re on autopilot following the line, but you’re not seeing too much of what’s really happening.”

He swam alongside circling sharks and a 10-foot swordfish. He scooped up a turtle the size of a bar of soap in blue water and spotted whales the size of cars. The only constant came in the form of loads of discarded plastic.

“We saw a lot of items we use on land, like plastic cups, straws, forks and spoons and oil containers,” he says. “It was depressing because you see amazing sea life, then you see the plastic that we infect the oceans with, and it’s not supposed to be there.”

The crew picked up the larger chunks, gathered micro bits with a net and took water samples to test for microfibers so small they’re invisible to the human eye.

Unlike other expeditions that collect samples from the ocean for a few weeks or a month, Lecomte’s expedition collected samples over hundreds of miles and five months. The quantity of debris in such a remote area stunned him.

“I think that’s the problem — we don’t think it’s that big of a problem, but it’s all due to what we do on land.”

He believes humans can halt the damage by changing our behavior — curbing use of single-use plastics, stopping the flow of plastics into the ocean and recycling goods.

“I’m not here to ban plastic, just to say there is a problem, and we can resolve it if we change our behavior ourselves,” he says.

Charlotte Vicks, the Austin-based director of engagement for Mission Blue, an organization working to create a network of protected marine areas around the world, and director of engagement for the EarthX eco-conference coming to Dallas in April, says Lecomte’s swim provides valuable evidence about the enormity of the plastics problem.

“Every single piece of plastic that’s in the ocean originated in somebody’s hands, and we’ve got to come to grips with the plastic pollution problem that we’re facing,” she says.

The cost of an expedition like this would be close to $2 million, which includes the support yacht, but people volunteered their time, equipment and services were donated, and products and services were provided at a discount. The remaining cost ended up being about $500,000, which was covered by grants, investors, sponsors, friends, family and Lecomte.