Clark Sherman is a professor in the Department of Marine Sciences at the University of Puerto Rico-Mayagüez.  Clark did his graduate work at the University of Hawaii at Manoa where he studied the geology and sea-level history of Pleistocene reefs on the island of Oahu.  He has continued studying the geology of both modern and fossil reef systems.  His recent focus has been on the geology and geomorphology of mesophotic coral ecosystems, deeper reefs between depths of ~50-100 m, and uses technical rebreather diving to access these environments.