Fun Facts about Leather-back turtle: 1. Leather-back turtles are the largest living sea turtle in the world. -The species can grow to be over 6 feet in length and up to 2,000 pounds when weighed. 2. Leather-back turtles are the deepest diving turtle world wide. -They can dive 3,900 feet under the water. 3. Leather-backs are named for there shell, that isn't hard unlike most sea turtles. 4. "Dermochelys coriacea" is the scientific name for this type of sea turtle. 5.Female Leather-back Sea Turtles will only come to surface once after being born to lay their eggs. As for males they never go to the surface again after birth. 6. Although these turtles can dive and stay under water for a VERY long time they do have lungs and have to go up to the surface for air.