Leslie is renowned for his dive history research and preservation. He works through organisations such as the Cayman Islands’ International Scuba Diving Hall of Fame (where he has been the executive director for nearly 20 years), the Commercial Diving Hall of Fame, the Academy of Underwater Arts and Sciences, the Santa Barbara Maritime Museum, the Historical Diving Society USA, among others. His interest in diving history was stoked when he acquired a copper and brass dive helmet handmade by the legendary Augustus Siebe, considered the father of diving. He has received numerous awards, including DEMA’s Reaching Out Award (2016), the Academy of Underwater Arts and Sciences NOGI Award for Education (2003), Beneath the Sea Diver of the Year Award (2013), the Wyland Foundation ICON Award (2010), and most recently, the 2022 California Scuba Service Award for “turning his passion for diving’s history into a way for thousands to understand and discover theirs.”