Most salmon sharks head south and roam the warm waters offshore of Hawaii, California and Mexico until the spring, when they begin their journeys back to Prince William Sound. Sometimes they stay underwater for weeks at a time without coming up to the surface. Others wander along the coast of Alaska, hunting along the currents that attract their food. A few sharks stay in Alaska all winter long, and survive the frigid waters by regulating their body temperature and behavior to keep warm. They may travel thousands of miles a year, and seem to travel alone. We're watching closely, and analyzing thousands of hours of data that they're sending back.