"It was right there," he says.
Now Marrero is more than 400 miles away, trying to readjust to life at his family's home in Puerto Padre, Cuba, days after U.S. officials sent him back.
The 28-year-old construction worker was one of 24 Cubans who scaled a lighthouse off the Florida Keys in May as they scrambled to make it onto U.S. soil before authorities nabbed them.
Lawyers argued the group should have the chance to stay in the United States. Family members begged to be reunited with their loved ones. And in a stranger-than-fiction twist, the Cubans slipped a secret message in a bottle out into the sea
, claiming the Coast Guard was mistreating them.
Marrero and three others are back in Cuba, speaking for the first time and making new allegations about their treatment in U.S. custody.
As a growing number of migrants make the dangerous trek from Cuba to the United States
, this thwarted group's interviews with CNN provide a rare glimpse into the journey -- and into what it's like for those who don't make it ashore.
The journey begins
The sky was still dark when the group quietly pushed a boat into the waters off Alamar, a maze of rundown Soviet-style bloc housing just east of Havana.
From the moment they set sail around 4 a.m. on that day in May, it was a risky journey. They piled into what's known as a "rústico," the makeshift, borderline-seaworthy boats Cuban migrants use to cross the Straits of Florida. Often, the rickety vessels break apart or capsize, leaving people stranded at sea.
The 20-foot wood rústico that left Cuba that morning was cobbled together with the few tools and materials available. The patchwork vessel looked older than many of its passengers.
Marrero knew it might not make it. He'd attempted the same dangerous crossing six years ago. That time, the motor died before the boat he was riding in had even left Cuban waters, Marrero says, and he spent a whole day rowing back to Cuba. He holds up his still-calloused hands as proof.
So when the group set sail this time, Marrero says he knew the risks. Their makeshift boat wasn't the only problem they faced. If a Cuban Navy patrol boat spotted them, they could be arrested, their craft seized.
As the migrants got out into open water, Marrero soon realized his second trip wasn't faring much better than his first.
The migrants were packed tight on the boat, crammed so closely together that when the rústico began taking on water, they hardly had enough room to bail out the flooding boat.
"It was bad. The weather got bad and we were squeezed together on a boat that was too small," says Dadier Hernandez, a migrant who sold his horse and cart to pay for a spot onboard.
When the boat's only motor began acting up, some tried to make repairs while others used small buckets and empty bottles to bail the water coming over the sides of the boat.
Even as their vessel foundered, the last thing any of the migrants wanted was to be rescued at sea. Under a special status known as "wet foot, dry foot" that grew out of the 1966 Cuban Adjustment Act, Cubans who set foot on U.S. soil are allowed to stay and put on a fast track to receive U.S. residency. Those intercepted at sea are sent back to Cuba unless they can prove they face persecution by the Cuban government.
'We thought we were on land'
Marrero and the other migrants thought the lighthouse would save them.
About 20 hours after leaving Cuba, they could see the Florida Keys. But they were worried.
They'd just seen a fishing boat pass by, and they feared someone would report them to the U.S. Coast Guard before they made it to shore.
So, Marrero says, they made for the closest structure in view: an abandoned lighthouse.
"We thought we were on land. If they say that it belongs to the United States, it must be part of the United States," says Liban Concepción Lío, who was trying to reach Florida to reunite with the uncle who raised him after his father died.
After hours of negotiations, the group surrendered to the Coast Guard, who took them into custody.
In a lawsuit filed soon afterward, the Miami-based Movimiento Democracia argued that climbing the 136-year-old, 109-foot-tall American Shoal Lighthouse was the same as landing on American soil.
Federal prosecutors said the migrants never made it to dry land and should be sent back to Cuba.
'People...were going crazy'
While the legal battle over their fate played out in court, a U.S. Coast Guard cutter was the migrants' home for 42 days.
In the distance, they could see their goal: the U.S. coastline. But they had no idea what was happening onshore. As detainees, they were not permitted to speak with family members or lawyers representing them in U.S. federal court.
Days slipped by without an update on their situation.
"Some of the people on our trip were going crazy from being there such a long time," Marrero says. "It was very stressful."
Desperate to get word out, they came up with an improbable plan: They would throw a message in a bottle into the sea.
To get paper, they asked the Coast Guard crew for results from the Union of European Football Association's tournament.
To send the message, they placed it inside a water bottle they'd saved and tied an inflated plastic glove they'd found to the top.
"We waited for the boat to get close to the coast and we threw it," migrant Sergio Farías Almaguer said. "It was our last resort."
In a handwritten letter in Spanish with a few English phrases, they used a universal distress signal to begin: "S.O.S. Please help me."
"We have spent 37 days sleeping on the floor, the food is for dogs," the letter reads. "They mistreat us up to the point of violence, and we already have comrades going crazy, this is Hell."
Coast Guard investigating
A fisherman handed the letter over to the Coast Guard after he found it bobbing at sea. Now, the agency says it's investigating. A spokeswoman declined to comment on the details of the allegations in the letter until the investigation is complete.
In their interview with CNN, the migrants detailed what they claimed was inhumane treatment. CNN has not independently verified their allegations.
After the letter surfaced last month, a Coast Guard spokesman said the migrants were held in the "most comfortable conditions possible."
"They were treated with care, compassion and respect during the past five weeks," Lt. Cmdr. Gabe Somma said at the time. "This was a very challenging situation for both the migrants and our Coast Guard crews as their case was adjudicated."
The migrants told CNN they ate and slept on the deck of the U.S. ship, with a tarp serving as their only protection from the sun and rain.
The migrants alleged that the crew aboard the Coast Guard cutter told them they needed to ask for permission to stand up and threatened them with metal batons, water hoses and pepper spray if they did so without authorization.
Dadier Hernandez says he was punished for complaining about a meal to a Coast Guard officer.
"I said to him, 'Could you ask your captain if they could cook the carrot, because we can't eat them like this?' and he said to me, 'I am going to handcuff you up front for standing without permission."
Hernandez says his legs were handcuffed to the front of the cutter for six days as punishment. Another time, Hernandez told CNN, he stood up to ask for water and had both his arms and a leg handcuffed for a day.
"That isn't humane," Hernandez says. "I don't think those people were humane."
Marrero says he still feels back pain from sleeping on the deck night after night. And he claims the migrants didn't get enough food.
After eating small meals of rice and beans twice a day, Marrero says he lost 15 pounds aboard the cutter.
Asked to respond to the allegations, the Coast Guard told CNN that detainees are treated humanely.
"Any restraint or use of force is limited to that which can reasonably gain compliance and to ensure the safety of our crews and the migrants alike," Coast Guard spokeswoman Marilyn Fajardo said in a written statement. "Migrants are fed twice a day aboard our cutters and are provided water and medical care."
After 42 days, a choice
Lawyers representing the group say their legal battle isn't over. But a federal judge's decision last month dealt a blow to their case.
U.S. District Judge Darrin Gayles ruled that the lighthouse didn't qualify as dry land
. And Coast Guard officials said they'd begin the repatriation process.
After 42 days in Coast Guard detention, officials gave the group a choice over where they'd head next, according to the migrants interviewed by CNN. Their options: Return home or head to the U.S. Naval Base in Guantanamo Bay, Cuba.
Twenty of them decided to go to Guantanamo while the court continues to weigh their case. But four of them opted to return home to Puerto Padre.
They decided to head back to Cuba to end the ordeal, they told CNN, adding that U.S. immigration officials had informed them that even if they went to Guantanamo, it was unlikely they'd be given a chance to come to the United States. At best, they would be sent to a third country, most likely Haiti, the officials said, according to the Cubans.
It's unclear what will happen next for the migrants in Guantanamo. Earlier this month, a judge ruled U.S. officials don't have to give them an opportunity to speak with their attorneys because they "are not being involuntarily detained by the government," according to court records.
The four would-be migrants who are back in Puerto Padre say they're still worried about their country's worsening economy and fear the United States soon will end the policies that give them a leg up once they reach U.S. shores. Analysts say fears about a possible policy shift are a major factor fueling a surge of Cuban migration.
As relations improve between the longtime Cold War enemies, Cuban officials have lobbied the U.S. government to end "wet foot, dry foot," which they say encourages Cubans to endanger their lives at sea.
After two failed trips to the United States, Marrero says the risk is still worth it.
His construction job in Cuba doesn't pay him enough to live on, he says.
"If the opportunity comes up," Marrero says, "I would probably do it again. Every other way of leaving here is too difficult."