Ziefle is President and CEO of Divers Alert Network (DAN). Ziefle first became associated with DAN in 1989 and served for 11 years as a volunteer before joining the board of directors. He has served as a director of various DAN affiliates including DAN, The DAN Foundation (Director Emeritus), IDAN, DAN Services, Accident & General Insurance Company and DAN Risk Retention Group. Over the years, he has provided legal counsel and fundraising support to several prominent ocean conservation organisations: Ships to Reef, American Academy of Underwater Sciences, National Marine Sanctuaries and Ocean Futures Society.