Martin Strel is a determined man. He aims to swim the length of the Mississippi River from Lake Itasca to the Gulf of Mexico. The 48-year-old marathon swimmer began his journey on July 4. He's still certain he'll make it to New Orleans by his self-imposed target date of Sept. 7. We caught up with him this week in Winona.

	Martin Strel prepares for Day 21 in the Mississippi. He began swimming from Lake Itasca on July 4. He says it will take 66 days to swim to New Orleans. (MPR Photo/Laurel Druley)

Sunburned and sore, Martin Strel of Slovenia began Day 21 smiling. He's got a big swim ahead - both today and further down the river.

"Many lakes, many dams," he mutters in thickly accented English. "After St. Louis, yeah, snakes, maybe alligators, a lot of traffic from big ships, the big sun very strong."

But he's still eager to get in the water.

"Today good day. I'm very happy here in Winona."

He doesn't let on that he's in any pain, but his crew says he has trouble sleeping for more than four hours a night.

	Strel faces many challenges in the swim, not least sunburn. His crew makes sure he's wearing lots of sunscreen. (MPR Photo/Laurel Druley )

Martin's son, Borut, says he's seen his father swim the length of the Danube River. Martin Strel holds the world record for swimming the longest distance non-stop. Borut is confident his dad will make it to New Orleans on schedule. He laughs when asked if his dad is crazy.

"For me, not crazy, because I know him. But for other people they think this is crazy idea. But you'll see it's possible," saya Borut Strel.

When asked if he'd ever do a similar swim, Borut laughs again and shakes his head.

Borut is part of the six-member support team. Some travel with him in kayaks, others drive along in the support van. Team member David Hale says Strel has the right attitude - mind over body.

	Strel holds the world record for the longest non-stop swim. He also holds the record for swimming the length of the Danube, and soon hopes to hold a similar record for swimming the Mississippi. (MPR Photo/Laurel Druley)

"After watching him swim the upper part of the river, it erased any doubts in my mind," Hale says. "He's a real athlete. Every day it seems like he gets stronger. He's a machine."

But Strel says this swim is about more than athleticism. He's trying to send a message of friendship, peace and the importance of clean rivers.

On land, Strel looks out of his element. He's eager to get started on his 11-hour daily swim. But first he and his crew take a tour of We-no-nah Canoe, one of Strel's sponsors. Company owner Mike Cichanowski shows Strel and his team how his canoes are made. We-no-nah donated the canoes which are a vital part of the swim.

It's crew member Matthew Mohlke job to keep Strel out of danger.

"We're kind of his eyes and his ears," Mohlke says. "He's got his head down all the time. We've got one man on either side and another out in front, looking for any obstacles that Martin might encounter."

	It takes a big team to help someone swim the Mississippi. Strel's crew includes three kayakers and a follow crew in the support van. (MPR Photo/Laurel Druley)

Mohlke says Strel's already made it through some of the biggest challenges of the trip. Strel battled four-foot waves for 11 hours on Lake Pepin. But Mohlke says the worst part of the river will be at the end of Strel's journey.

"There's an area down in New Orleans called Cancer Alley. It's what they refer to as a dead zone," Mohlke says. "It's about 80 miles of oil, pollution, alligators. It's just awful. Martin will try to keep his head above water."

But that's going to be in about a month. Today's challenge is to get to La Crosse - about 35 miles.

Having finished the tour of the canoe company, Strel and his team load into the van and rush the put-in point. It's the lock and dam across the bridge in Wisconsin.

While his kayakers get ready and ease into the river, Borut rubs sunscreen on his father's face and neck. Strel's goggles seemed to have made a dent on the bridge of his nose.

A few people from Winona have come to see him off. He sits down on the dock, puts on his flippers and lowers his goggles.

"Good-bye!" He slips into the waters and pulls away with strong, even strokes.

He sets a steady pace for several miles. At one point Strel swims too close to the shore, getting dangerously near some rocks. The kayakers blow a whistle and shout for him to change course.

His teammates not only keep him in line but they keep him laughing, too. They pass a no-wake zone sign and Hale yells out, "Tell Martin not to make a wake!"

A passing sand barge throws about a three-foot wake, but causes no problem for the world-class swimmer.

Canoe designer Dave Kruger is paddling along for the morning. He's impressed by his speed.

"He'll be in La Crosse in no time," he says.

And then only 45 more days to go.