Mayer completed the Higher School Certificate in 1983 at North Sydney Boys High School. He joined the Royal Australian Naval College in 1984 as a seaman specialist, and on completion of initial training Mayer gained Bridge Watch-keeping Certificates on board and. Mayer completed training as an Air Intercept Controller and returned to sea in HMA ships and, including service aboard Sydney "as Air Intercept Control Officer and Boarding Officer during that ship's operational deployment to the Persian Gulf during the 1990–91 Gulf war." In 1993 Mayer commenced training as a Principal Warfare Officer and graduated with distinction in 1994. As Direction Officer, Mayer served aboard both and, undertaking a wide range of regional deployments and operations, including service as the Task Unit Operations Officer during Operation Stabilise – ADF operations in support of East Timorese independence. In January 2000 Mayer was promoted to commander and posted to the United States as the first ADF Liaison officer to US Joint Forces Command based in Norfolk, Virginia. Mayer returned from the United States in mid-2002 and assumed command of HMAS Canberra, continuing an association with that ship that included service in every rank from trainee to commanding officer. Mayer left HMAS Canberra in July 2004 and was promoted to the rank of captain and assumed the position of Chief Staff Officer at Maritime Headquarters Australia in January 2005. While posted to MHQ, Mayer was seconded to the Australian Maritime Deployable HQ staff for duties as Commander Task Group 58.1 – Northern Arabian Gulf Maritime Security Operations Commander. Mayer was awarded a Commendation for Distinguished Service for his "distinguished performance" in this role. Mayer returned to MHQ in October 2005, resuming duties as Chief Staff Officer. His "outstanding achievement" while with MHQ led to the award of a Conspicuous Service Cross in 2008.
Senior commands
In January 2007 Mayer attended the Australian Defence College and read for a Master of Arts in Strategic Studies. He assumed command of the frigate in December 2007 and completed deployments to exercise RIMPAC and to Southeast Asia as the Commander of the RAN Task Group. Mayer left Anzac in mid-2009, was promoted to commodore and appointed Commander of the multi-national International Stabilisation Force in East Timor on 24 October 2009. The first non-army officer to hold this command, Mayer demonstrated "inspirational leadership and initiative, and outstanding dedication to duty in stable but fragile security environment" during his six-month deployment, for which he was awarded a Bar to his CSC and the East Timorese Medal of Merit. On Mayer's return to Australia in April 2010, he assumed duties as Commodore Flotillas at Fleet Headquarters. Promoted to rear admiral, he was appointed Commander Australian Fleet on 12 June 2014. In recognition of his "selfless devotion to duty and outstanding achievement" in these senior roles, Mayer was made an Officer of the Order of Australia in the 2017 Australia Day Honours. He relinquished command of the Australian Fleet to Rear Admiral Jonathan Mead in January 2018 and was appointed as Head Force Design within the Vice Chief of Defence Force Group from March. In April 2019 it was announced that Mayer would be appointed Deputy Commander United Nations Command in South Korea later in the year. He relinquished Head Force Design in June and, promoted vice admiral on 18 July, succeeded Lieutenant General Wayne Eyre of the Canadian Army as Deputy Commander on 28 July. He is the second non-American and first Australian to hold the post in the 69-year history of United Nations Command. Mayer is a graduate of the Australian Institute of Company Directors, holds a Bachelor of Arts from the University of New South Wales, a Master of Arts from Deakin University, and a Master of Business Administration from the University of Southern Queensland.
Personal life
Mayer is married to Susanne, with whom he has four children. Mayer's interests include rugby, sailing, bushwalking and kayaking.
