Peter Ehlers was born 1943. He studied law at Marburg and Kiel University. After having written his doctoral (PhD) dissertation about IMO he joined the German maritime administration in 1970. He worked for many years in the Maritime Transport Department of the Federal Ministry of Transport where he became Deputy Director General. From 1989 to 2008 he was the President of the Federal Maritime and Hydrographic Agency, the central maritime authority in Germany. He represented his country in various international maritime organizations, e. g. IMO, IHO, UNESCO-IOC, Helsinki-Commission; he was twice Chairman of the Helsinki Commission and chaired two International Hydrographic Conferences of IHO. He was a member of numerous German maritime institutions and organizations. He retired in 2008.

Since 1992 he has been teaching law of the sea at Hamburg and Rostock University. In 2002 he became Professor at Hamburg University; in 2007 he was awarded Dr. h.c. at Rostock University. Until its closure in 2014 he was member of the Board of Directors of the International Max-Planck Research School for Maritime Affairs, Hamburg. After his retirement he was appointed Chairman of EUROGOOS, an association of European oceanographic institutes; the chairmanship terminated end of 2013. He is a member of the Board of Governors of the World Maritime University, Malmö. He is a guest lecturer for law of the sea and marine environment law at the World Maritime University, Malmö, and the International Law Institute, Malta.