The lure of a mojito, the world’s most prized cigars, the rich Cuban culture and a chance to see the Pope were not enough to fill seats on what was to be the inaugural flight between Baltimore-Washington Thurgood Marshall International Airport and Havana.

The March 21 charter flight has been postponed until fall, and the head of the travel agency that planned weekly service between BWI and Cuba says the agency will try again in October and improve its publicity campaign.

“We’ve had lots of calls and lots of interest, but that hasn’t translated into ticket sales,” said William J. Hauf, president of Florida-based Island Travel and Tours. “We probably could have filled up the first flight, but we want to offer these flights on a weekly basis, and right now we weren’t confident we’d sell enough tickets for the second and third flights to cover a cost of $50,000 to $60,000 per flight.”

Hauf said that Island had just six confirmed ticket sales for next month’s flight.

Charter flights to Cuba are offered from other U.S. cities, and March 21 seemed like a good launch date for Island Travel to begin offering the service from BWI. In addition to the attractions of an island that generally has been off limits to Americans since the communist takeover, the Pope’s three-day visit to the country, scheduled to begin March 26, also seemed likely to encourage ticket sales.

Vacation tourism to Cuba is still prohibited for U.S. citizens under federal restrictions mandated during the Cold War and still supported by many Cuban-Americans whose families fled after Fidel Castro came to power.

The charter flights are open to academics, journalists, religious institutions, cultural groups and other organizations that show a purpose other than tourism for the visit. Travelers are subject to daily spending limits and are prohibited from bringing home Cuban souvenirs or other goods.

Though Island travel has been promoting the BWI flights since January, Hauf said many religious and educational organizations need a longer lead time to plan such an excursion.

“We’re going to continue to promote this heavily so that when we begin [BWI] flights, probably in October, these groups will have had plenty of time to work it into their plans,” Hauf said.