Andrew Noymer, a public health professor at the University of California, Irvine, said it was sensible to start reopening beaches and see how it goes. People should make their own risk assessment, but he said the sun helps kill germs and the virus is less likely to spread in the ocean. “We have to start reopening the United States slowly and smartly. We can’t just keep everyone locked inside for 12 months,” Noymer said. “If we can’t run on the beach then how on Earth can we go to a restaurant or a movie theater?”