When cruise ships depart from Florida’s ports in the coming months, some won’t require passengers to get the most effective pandemic life preserver there is — a Covid-19 vaccination. That’s because of new legislation Florida Gov. Ron DeSantis signed that bars businesses from requiring customers to show proof of vaccinations. The law goes into effect Thursday and opponents say it could threaten the recovery of an industry that is vital to the state’s economy, in addition to making it difficult for cruise ship companies to put some teeth into the federal Centers for Disease Control and Prevention vaccination recommendations. At...