Byron Alvarez slipped as he prepared to plunge into Istanbul's Bosphorus Strait.

It was not the greatest way to start the 30th Bosphorus Cross-Continental Swimming Race. But the Tracy native had quite the finish.

With a time of 1 hour, 8 minutes, 23 seconds, Alvarez finished fourth in the 65-69-year-old age group in the July 22 event that featured upwards of 2,400 swimmers from 42 countries.

The swim, which is organized by the Turkish Olympic Committee, covers four miles through the Bosphorus Strait, starting from Kanlica in Asia and finishing at Kurucesme Cemil Topuzlu Park in Europe.

It’s no easy swim, but it’s one Alvarez, who owns a commercial real estate firm, has been working towards for some time.

The 65-year-old has always loved the water, he said. He was a springboard diver in high school, and first signed up for an open water swim in the mid-1980’s, the famed trek from Alcatraz to San Francisco.

From there, he was sold.

“The first five minutes, it’s like piranhas going after prime rib,” Alvarez said. “But after 15 minutes, it becomes a solo swim, and you really get into a zone.”

Alvarez said he’s since done the Alcatraz swim 13 times, and others like the swim from Lanai to Maui in the Hawaiian islands 18 times.

“I try to stay active,” Alvarez said. “I don’t want to have ‘he was a great TV-watcher’ on my tombstone.”

About a year ago, Alvarez began training with Dave Breitenbucher of the California Gold Masters club. Breitenbucher helped Alvarez refine his stroke and incorporate more of his legs into his swimming motion for a faster, more efficient move through the water.

Fast-forward to late July, and Alvarez was trained and ready to swim continent-to-continent. In the pre-race meeting, Alvarez said, he found certain checkpoints to follow as he moved through the race.

“Really good course management,” Alvarez said. “That’s everything.”

And it was. After the initial slip-up, staying on course was Alvarez’s main focus during the race. He kept his vision on landmarks like prominent bridges at different points, and finally the giant balloons marking the finish line at Kurucesme.

That’s really all there’s room for — focusing to keep oneself on track even as others may veer off. There’s barely even time to think about what else might be in those waters, though Alvarez said it crosses his mind every now and again.

“Anything in the water, other than water, is going to spook you,” he said, noting the only thing he came face-to-face with was an empty Doritos bag. “I try not to look down.”

Alvarez has the Maui Channel swim planned at the end of August, as well as ambitions to swim more casual, relaxed events in different spots around the world. The Bosphorus swim, though, provided all the confidence he needed to consider more races down the road.

He said the the best part of the cross-continent course — or any course, for that matter — wasn’t crossing that finish line. It was the moment, near the midpoint of the race, when he was able to take a moment to let the experience wash over him.

“It’s always when you’re in the middle of the race,” Alvarez said, “and you just take a quick peek, look around and say, ‘this is so cool.’”