Shares of Carnival Corp. /zigman2/quotes/202325446/composite CCL -1.98% rose 0.9% in premarket trading Monday, after the cruise ship operator confirmed its plans to resume cruising from a U.S. port during the July 4 holiday weekend. The company said its Carnival Vista ship will resume guest operations on July 3 from the Port of Galveston in Texas, and its Carnival Breeze ship will resume operations on July 15. The company said the cruises are available for people who have proof of being fully vaccinated, in accordance with guidelines laid out by the Centers for Disease Control and Prevention (CDC). "We appreciate the progress and support for our U.S. restart from the CDC and other key federal agencies; however, the current CDC requirements for cruising with a guest base that is unvaccinated will make it very difficult to deliver the experience our guests expect, especially given the large number of families with younger children who sail with us," said Christine Duffy, president of Carnival Cruise Line. "As a result, our alternative is to operate our ships from the U.S. during the month of July with vaccinated guests." The stock has rallied 41.0% year to date, while the S&P 500 /zigman2/quotes/210599714/realtime SPX -1.10% has gained 12.6%.