This document discusses four popular diving sites in Tobago: Mount Irvine Wall, The Sisters, Kelleston Drain, and Bookends. Mount Irvine Wall is an easy dive featuring beautiful canyons and large schools of fish. The Sisters features bizarre underwater scenery, caves, lobsters, stingrays, nurse sharks, and occasionally hammerhead sharks. Kelleston Drain is known for its huge brain coral and features giant green moray eels and nurse sharks. Bookends gets its name from strangely shaped rocks and features nurse sharks and turtles within its natural amphitheater setting.