WASHINGTON–On Nov. 11, retired Marine Gunnery Sgt. Jay Platt was blindfolded,  handcuffed and shackled, then he jumped in the Mississippi River.

In 50-degree water, high winds and towering waves, he swam the 1.88 miles to the other side.

“I do not recommend it,” he laughed.

Platt, who’s nicknamed Mr. Unstoppable, was not a kidnap victim or being hazed in a really bad fraternity prank. Instead, he voluntarily jumped in the frigid waters and made this daring swim to raise money for the Wounded Warrior Project, a charity for military men and women injured in the line of duty.

Jay Platt, who was forced to retire early from gunnery sergeant in the Marines due to complications from a rare kidney cancer, braves the cold waters of the Mississippi River. (Photo provided)

“Though I’m not combat wounded, I know what they must feel like. Mentally, that can play a big negative role in your life if you allow it to,” he said.

About halfway through the Mississippi swim, Platt, 45, began to think that he might have bitten off more than he could chew. But focusing on war veterans helped him calm down and push forward.

“I’m giving these men and women hope,” he told himself.

Platt has experienced his fair share of suffering and overcoming the impossible himself.  In 1998, Platt was forced to retire early from his position as a gunnery sergeant in the Marines due to complications from a rare kidney cancer. He was only 32.  Platt also lost an eye while in the Marines, and today suffers from brain and spinal tumors.

When he had to take medical retirement after 15 years in the Marines, Platt was told by doctors that the best years of his life were behind him. Maybe it’s part of the Marine spirit, or maybe it’s because it’s just how he was raised, Platt said, but he made the decision at that moment that he wasn’t going to quit.

“I said, ‘I’m not going to give up.  I’m going to keep fighting this.’”

And he also wanted to fight for veterans who, due to combat injuries, are going through their own medical problems.

So began his exploits to raise money for the Wounded Warriors Projects.

In 2005, he swam from Alcatraz to San Francisco with his feet and hands tied, becoming one of three people to make that swim in such a way. He said the swimming style looks something like that of a dolphin.

In 1999 he hiked the 2,100-mile Appalachian Trail. Platt’s next goal is to climb Mt. Everest for his 50th birthday.

And should Mr. Unstoppable ever feel a lack of confidence, he just repeats an old mantra: “Like we say in the Marines: Never quit, never die, always Semper Fi.”