Norwegian Cruise Lines has extended its weekly roundtrip cruises from Miami to Cuba, adding 33 new departures through 2018.

The Norwegian Sky begins its 2018 Cuba cruise season next March, sailing four-day roundtrip cruises from Miami, with 32 of the cruises to include an overnight stay in Havana, as well as a call on Great Stirrup Cay, the cruise line’s  private island in the Bahamas.

In Havana, Norwegian is offering a selection of 15 half and full-day excursions, including a farm-to-table dining experience and a tour of the city in a classic car–an iconic experience in the city.

These new cruises begin on March 26, 2018, and are in addition to the previously announced 30 calls that Norwegian will offer through December 2017.  Free drinks are reportedly part of the package.

While Norwegian is boosting cruises, airlines like American and JetBlue that initially jumped on the Cuba bandwagon with heavy flight schedules, have cut back those flights citing lower demand than expected and two smaller American airlines, Silver Airways, and Frontier Airlines, have canceled their planned flights altogether.

The Cuban government website Cubadebate reported a massive spike in cruise port calls to the country in 2015, jumping from 24 in 2012 to 139 in 2014 with visits by passengers spiking from 6,770 to 37,519 in the same period.

The takeaway may be that cruising to Cuba is the more popular form of travel to the newly opened country, while independent travel via air has yet to catch up.

Factors may be the issue of the dearth of currently available on-island hotel accommodations and the inconsistent quality of food and dining experiences that travelers have reported. Cruise passengers get to bypass those issues and still experience the culture, sites, and textures of Havana and the surrounding region.

Norwegian Sky’s four-day cruises to Cuba open for sale on April 20.