On a windy morning in March, two older surfers at LeCount Hollow Beach, on Cape Cod, look out at the gray Atlantic. The surfers, too, have started to migrate, with many now surfing exclusively in the winter — not to avoid the crowds in this popular summer tourist destination, but to avoid another growing demographic: great white sharks. Researchers can then use these to study where great white sharks spend their time, when they arrive, and when they leave. A hotter color around a specific beach or area would signify a higher likelihood of running into a great white. Whether Cape Cod will become a model for coexistence is an open question.