Hammond joined the Royal Australian Navy (RAN) in 1986 as a junior sailor electronics technician and attended recruit school at HMAS Cerberus.

[2][3][4] Graduating from the academy with a Bachelor of Science in 1990, he was promoted sub-lieutenant and completed seamanship and navigation training before volunteering for the RAN Submarine Service.

He attended the Australian Command and Staff College the following year, graduating with a Master of Management in Defence Studies from the affiliated University of Canberra.

He also gained a Master of Maritime Studies from the University of Wollongong in 2005, served on an operational exchange posting with the Royal Navy Submarine Service and, following his return to Australia, was appointed commanding officer of HMAS Farncomb.

[4] In the 2023 King's Birthday Honours, Hammond was advanced to Officer of the Order of Australia for his "distinguished service" and "exceptional leader[ship]" in senior command roles.

[8][9] Hammond was awarded South Koreas Order of National Security Merit, 2nd Class[10] and in October 2024 the Meritorious Service Medal by Singapore's Minister for Defence, Ng Eng Hen.