Jeff is the President of Next Generation Services, where he provides consulting and training services in the diving market. Clients include rebreather manufacturers, training agencies, and legal agencies. Jeff has participated or lead over 70 diving expeditions during the past 30 years, to places like Palau, Canary Islands, and Antarctica. Jeff was certified as a NAUI Instructor in 1978, and is active in teaching cave diving, rebreather, nitrox, decompression, and trimix diving courses. He has published extensively on diving education topics, with heavy emphasis on diving safety. Jeff has edited/reviewed many diving textbooks, and is the author of Mastering Rebreathers. He has served on several Boards of Directors in the diving community, including as Chairman of the NSS-CDS and as Vice Chairman of NAUI, and as Treasurer on the AAUS Board. In 2007 he was honored as the DAN/Rolex Diver of the Year and in 2015 He was the recipient of the AAUS Conrad Limbaugh Award for Scientific Diving Leadership. He recently returned from diving and testing rebreathers at McMurdo Station, Antarctica.