Much of the shark focus around the Cape is on great whites roaming close to the shoreline as they prowl for seals, but researchers are finding out that several sharks are actually diving deep into the twilight zone out in the middle of the ocean. Scientists at Woods Hole Oceanographic Institution on Cape Cod are researching the sharks’ deep diving behavior and how sharks’ bodies have evolved to handle these deeper conditions. They’re learning that deep diving is far more frequent and extensive across species than previously thought, said Simon Thorrold, a senior scientist in the biology department at the Woods Hole Oceanographic Institution.