You might assume that with the thawing of relations between Cuba and the U.S., Cubans would see positive change at home, and less reason to attempt the perilous water crossing to Florida. You'd assume wrong.

U.S. law enforcement authorities are confronting a surge of Cuban migrantstrying to make the journey by boat across the Florida Straits: the highest numbers they've seen in two decades.

"It's gotten busier and busier," says U.S. Coast Guard Captain Jeff Janszen, commander of sector Key West, Fla.

Over the past fiscal year, the Coast Guard intercepted 5,396 Cuban migrants who were attempting the crossing. That's nearly twice the number from the previous year. About 1,000 Cubans managed to evade detection and make it to U.S. shores.

The recent arrivals include Yojany Pacheco, 33, from Ciego de Avila, Cuba.

He and a group of friends pooled their money – the equivalent of several hundred dollars apiece – and built a boat in secret, in the Cuban forest. They got boards for the frame and a car engine from an old Peugeot which they mounted in the middle of the vessel.

After a week of labor, the boat was ready to sail.

Pacheco pulls out his smartphone and proudly shows us videos he shot on their voyage north.

We see 14 Cubans packed into a small wooden boat — 13 men and one woman. They're wearing ball caps, grinning big and giving optimistic thumbs up as they chug away from their homeland. The sun is rising behind them.

Pacheco opens Google maps and points to the route they followed: the path goes from a red dot along the Cuban coast near Laguna de Leche to a gold star outside Marathon, Fla., midway up the Keys.

The trip was about 200 nautical miles and it took them three days.

Success on the sixth try

Pacheco, who has a degree in math, physics and IT, says he was driven to leave Cuba because he couldn't make a living. Also, since he had tried to leave five times before, he was suspected of being a smuggler, and was harassed by Cuban authorities.

On his fifth attempt, this past April, Pacheco made it almost all the way to Florida, sailing tantalizingly close to Key Largo.

"We could see the beach, the yachts, the boats and cars, everything," he recalls. But his boat was intercepted by the Coast Guard, and he and his fellow rafters were sent back home.

"So," he says, "I built another boat. And here I am!"

When they finally landed in Florida on Sept. 9, Pacheco says, "my eyes filled with tears. I looked around and everybody was crying. We hugged each other. Our dream came true."

Under U.S. immigration policy known as "wet foot/dry foot," Cubans who are caught at sea ("wet feet") are sent back home. But those who manage to reach American soil ("dry feet") can stay legally in the U.S., get benefits, and are put on a fast track toward citizenship.

Cuba is the only country that has that special status, which dates back to the Cold War. It's designed to protect Cubans fleeing political persecution under the communist Castro regime.

But now, most Cubans who are leaving are economic migrants seeking better opportunity in the U.S., not political refugees.

Will The Policy Change?

Critics of "wet foot/dry foot" say the policy no longer makes sense as the U.S. and Cuba normalize relations.

They note that many Cubans travel back and forth to Cuba once they become permanent legal U.S. residents, clearly not fearing persecution.

Amid fears that the policy will change and their unique immigration status will end, the migrants are becoming more desperate to reach U.S. shores.

"It's amazing to me what they'll do," says Janszen, the Coast Guard captain. "We saw one last year where they actually held an infant child over the side of the boat to get us to back off, and we did. Thank God they didn't drop the child overboard."

Coast Guard crews have seen others intentionally wound themselves in hopes they'll be sent to the U.S. for medical care and allowed to stay.

"They've cut themselves. They've shot themselves," Capt. Janszen recounts. "We've seen them drink bleach. We've seen them drink gasoline. You just can't make this stuff up."

Many Cubans figure this might be their last, best chance to get into the U.S. before immigration becomes much more difficult.

So, it's a cat-and-mouse game. The Cubans try to sneak through, and it's up to the Coast Guard and border patrol to keep them out.

A hot spot for landings

To get a view from the water, we ride out from Key West on a fast boat with John Apollony, a marine interdiction agent with U.S. Customs and Border Protection.

We cruise through gorgeous turquoise waters and stop by an uninhabited island covered with mangrove trees about 20 minutes from Key West.

It's part of the Marquesas Keys, a hot spot for Cuban migrant landings. The islands are remote enough that Cubans figure they have a better chance of avoiding interdiction.

Apollony scans the beach through binoculars and counts nine abandoned Cuban chugs along just one small stretch of shoreline.

Border patrol agents are confronting migrants who are more emboldened than ever, Apollony says.

"They don't want us coming near them, and they're gonna do everything to get their vessel to shore," he says. "Sometimes they'll have homemade weapons on board — machetes, jagged oars – and they will swing 'em at you or threaten you to try to keep you away from them."

U.S. administration officials have been tight-lipped about any potential changes to U.S. migration policy with Cuba.

But according to Coast Guard Capt. Janszen, if "wet foot/dry foot" were to end, there is a plan to handle an eventual Cuban exodus.

"We'd have to not just have additional Coast Guard assets," he explains. "We'd probably need Department of Defense assets. Navy assets. We'd probably open up camps in Guantanamo Bay, Cuba, which we had to do actually in the '90s. So there is a plan in place to deal with a mass migration, if it comes to that."

In 1994, Fidel Castro opened the doors to anyone who wanted to leave the island after a series of anti-government demonstrations. He blamed U.S. policy for the rioting in Havana and threatened to unleash a mass exodus to South Florida. More than 35,000 Cubans took to sea before President Clinton declared an immigration emergency, ordering the Coast Guard to intercept the rafters. Many ended up in camps in Guantanamo and Panama before being allowed to migrate to the U.S.

A Constant Flow

Meantime, the Cuban flow shows no sign of abating, despite the well-known dangers of the crossing.

Just days before we visited, a crowded Cuban boat capsized off the Florida Keys.

Three of the migrants on board made it to shore.

Four others were found dead. Sixteen more were missing and presumed drowned.

The Cubans who do complete the crossing are processed by border patrol, and then turned over to two church groups in Miami.

The migrants are fed, given new clothes, and put up in motels. They're granted work permits.

If they don't have family in Florida, they're sent on to live in cities around the country with programs in place to help them find work.

Yojany Pacheco has a job lined up in a restaurant in Albuquerque, N.M. Another recent arrival, Arnalbis Rogel, 45, from Havana, says he'll take any work he can get. When we met, he was about to be sent from Miami to Houston.

Leaving Family Behind

Rogel left his wife and three children back in Cuba. The youngest is just 14-months-old. He pulls out photos of his kids from his wallet, smiles wistfully and taps his heart.

"I know that I have to be strong, because this is the only way I'll give them a better life," he says.

Rogel worked as a baker and candy maker in Havana. He was unemployed for five months until finally he decided to leave.

He spent 25 nervous hours at sea.

"The sea has an ugly face," Rogel recalls, and he vows that no one else in his family will make the same journey.

His group of rafters called themselves the Vikings. When their boat landed in Key Biscayne on Sept. 7, "we jumped up and down and rubbed our bodies with sand!" Rogel says, laughing and jumping and gesturing with his hands to demonstrate.

The boat's navigator was Modesto Morales, 58, a truck driver from Havana. Describing the journey, he says, "You're tense from the moment you start until you land. You're looking around. If someone says, 'There's a light!' – 'Where?' We had to slow down, so we would pull in at night to avoid the Coast Guard."

With his boat mate, Arnalbis Rogel, Morales was heading for a new life in Houston. "It doesn't matter where I go," he says, "because anywhere, anywhere will be better than Cuba."

Morales says that even with the thawing of relations between the two countries and President Obama's trip to Cuba earlier this year, for regular people, it means nothing.

"Nothing has changed," he says. "For us, it's all the same. No transportation, no jobs, very low salaries. Lots of talk, but no change."

Morales adds, "In Cuba, there is no freedom of speech. Everything you say is a crime."

Morales and Rogel both say they decided to get out of Cuba now while they still had the chance. They're among those who fear that the days are numbered for Cubans' preferential treatment under immigration law.

"If wet foot/dry foot ends," Morales warns, "we Cubans, we're lost!"

Arnalbis Rogel adds a political footnote.

"I told the guys, 'We have to build the boat in record time because elections are coming! We don't know who's going to become president of the U.S., and we don't know what changes will come.'"

These recent arrivals face an uncertain future in an unfamiliar land. But they seem to have no regrets.

Copyright 2016 NPR. To see more, visit http://www.npr.org/.