Carnival's Adonia cruise ship arrives from Miami in Havana, Cuba, Monday, May 2, 2016. The Adonia's arrival is the first step toward a future in which thousands of ships a year could cross the Florida Straits, long closed to most U.S.-Cuba traffic due to tensions that once brought the world to the brink of nuclear war. (AP Photo/Ramon Espinosa)

Carnival's Adonia cruise ship arrives from Miami in Havana, Cuba, Monday, May 2, 2016. The Adonia's arrival is the first step toward a future in which thousands of ships a year could cross the Florida Straits, long closed to most U.S.-Cuba traffic due to tensions that once brought the world to the brink of nuclear war. (AP Photo/Ramon Espinosa)

Passengers stand on the deck of Carnival's Adonia cruise ship as they arrive from Miami in Havana, Cuba, Monday, May 2, 2016. Havana's Christ statue stands behind. The Adonia's arrival is the first step toward a future in which thousands of ships a year could cross the Florida Straits, long closed to most U.S.-Cuba traffic due to tensions that once brought the world to the brink of nuclear war. (AP Photo/Ramon Espinosa)

Passengers stand on the deck of Carnival's Adonia cruise ship as they arrive from Miami in Havana, Cuba, Monday, May 2, 2016. The Adonia's arrival is the first step toward a future in which thousands of ships a year could cross the Florida Straits, long closed to most U.S.-Cuba traffic due to tensions that once brought the world to the brink of nuclear war. (AP Photo/Ramon Espinosa)

Passengers on board Carnival's Adonia cruise ship wave flags as they arrive from Miami in Havana, Cuba, Monday, May 2, 2016. The Adonia's arrival is the first step toward a future in which thousands of ships a year could cross the Florida Straits, long closed to most U.S.-Cuba traffic due to tensions that once brought the world to the brink of nuclear war. (Joe Cavaretta/South Florida Sun-Sentinel via AP)

People take photos as Adonia leaves port in Miami, Sunday, May 1, 2016, en route to Cuba. After a half-century of waiting, passengers finally set sail on Sunday from Miami on an historic cruise to Cuba. Carnival's Cuba cruises, operating under its Fathom band, will visit the ports of Havana, Cienfuegos and Santiago de Cuba. (Patrick Farrell/The Miami Herald via AP)

A woman from Cuba waves Adonia leaves port in Miami, Sunday, May 1, 2016, en route to Cuba. After a half-century of waiting, passengers finally set sail on Sunday from Miami on an historic cruise to Cuba. Carnival's Cuba cruises, operating under its Fathom band, will visit the ports of Havana, Cienfuegos and Santiago de Cuba. (Patrick Farrell/The Miami Herald via AP)

Passengers on board the Adonia watch as the ship leaves port in Miami, Sunday, May 1, 2016, en route to Cuba. After a half-century of waiting, passengers finally set sail on Sunday from Miami on an historic cruise to Cuba. Carnival's Cuba cruises, operating under its Fathom band, will visit the ports of Havana, Cienfuegos and Santiago de Cuba. (Joe Cavaretta/South Florida Sun-Sentinel via AP)

Carnival's Adonia cruise ship arrives from Miami in Havana, Cuba, Monday, May 2, 2016. The Adonia's arrival is the first step toward a future in which thousands of ships a year could cross the Florida Straits, long closed to most U.S.-Cuba traffic due to tensions that once brought the world to the brink of nuclear war. (Ismael Francisco/Cubadebate via AP)

People display a U.S. flag as they wait for Carnival's Adonia cruise ship to arrive from Miami, in Havana, Cuba, Monday, May 2, 2016. The Adonia's arrival is the first step toward a future in which thousands of ships a year could cross the Florida Straits, long closed to most U.S.-Cuba traffic due to tensions that once brought the world to the brink of nuclear war. (Ismael Francisco/Cubadebate via AP)

People watch Carnival's Adonia cruise ship arrive from Miami, in Havana, Cuba, Monday, May 2, 2016. The Adonia's arrival is the first step toward a future in which thousands of ships a year could cross the Florida Straits, long closed to most U.S.-Cuba traffic due to tensions that once brought the world to the brink of nuclear war. (AP Photo/Ramon Espinosa)

Cuban soldiers watch the Carnival Adonia cruise ship arrive from Miami, in Havana, Cuba, Monday, May 2, 2016. The Adonia's arrival is the first step toward a future in which thousands of ships a year could cross the Florida Straits, long closed to most U.S.-Cuba traffic due to tensions that once brought the world to the brink of nuclear war. (AP Photo/Ramon Espinosa)

Rick Schneider of Delray Beach waves a Cuban flag onboard the Adonia as the ship leaves port in Miami, Sunday, May 1, 2016, en route to Cuba. After a half-century of waiting, passengers finally set sail on Sunday from Miami on an historic cruise to Cuba. Carnival's Cuba cruises, operating under its Fathom band, will visit the ports of Havana, Cienfuegos and Santiago de Cuba. (Joe Cavaretta/South Florida Sun-Sentinel via AP)

Carnival's Adonia cruise ship arrives from Miami in Havana, Cuba, Monday, May 2, 2016. The Adonia's arrival is the first step toward a future in which thousands of ships a year could cross the Florida Straits, long closed to most U.S.-Cuba traffic due to tensions that once brought the world to the brink of nuclear war. (AP Photo/Ramon Espinosa)

Carnival's Adonia cruise ship arrives from Miami in Havana, Cuba, Monday, May 2, 2016. The Adonia's arrival is the first step toward a future in which thousands of ships a year could cross the Florida Straits, long closed to most U.S.-Cuba traffic due to tensions that once brought the world to the brink of nuclear war. (AP Photo/Ramon Espinosa)

People watch Carnival's Adonia cruise ship arrive from Miami, in Havana, Cuba, Monday, May 2, 2016. The Adonia's arrival is the first step toward a future in which thousands of ships a year could cross the Florida Straits, long closed to most U.S.-Cuba traffic due to tensions that once brought the world to the brink of nuclear war. (AP Photo/Ramon Espinosa)

The cruise ship Adonia, from the new Carnival's Fathom line, sails Miami's port escorted by tugboats as it heads to Cuba on May 2, 2016 in Miami, Fla. Adonia, with a capacity of 704 passengers, is the first American cruise line to make a voyage to Cuba in about 50 years. (Gaston De Cardenas/EFE/Zuma Press/TNS)

The cruise ship Adonia, from the new Carnival's Fathom line, sails Miami's port escorted by tugboats as it heads to Cuba on May 2, 2016 in Miami, Fla. Adonia, with a capacity of 704 passengers, is the first American cruise line to make a voyage to Cuba in about 50 years. (Gaston De Cardenas/EFE/Zuma Press/TNS)