The State Department announced that "going forward, the United States will prohibit US travelers from going to Cuba under the previous 'group people-to-people educational' travel authorization. In addition, the United States will no longer permit visits to Cuba via passenger and recreational vessels, including cruise ships and yachts, and private and corporate aircraft."
https://www.cnn.com/2019/06/04/politics/us-cuba-travel-restrictions/index.html
https://www.cnn.com/2019/06/04/politics/us-cuba-travel-restrictions/index.html