Additionally, the Duke held the highest honorary ranks in the New Zealand Defence Force. He was made Admiral of the Fleet of the Royal New Zealand Navy during a solo visit to New Zealand in 1958 on the Royal Yacht Britannia, and to commemorate the Queen's silver jubilee in 1977 he was made Field Marshal of the New Zealand Army and Marshal of the Royal New Zealand Air Force. The Duke was patron of the Royal New Zealand Yacht Squadron, reflecting his lifelong love of the sea and sailing, and patron of the New Zealand Society in the United Kingdom. He was a life member and Badge in Gold award holder of the Royal New Zealand Returned and Services Association, and life member of Aviation New Zealand and the Tin Hat Club. He was an honorary member of the Royal Naval Volunteer Reserve Veterans Association and the Wellington Club. He was also involved with a number of Commonwealth associations, such as the Royal Agricultural Society of the Commonwealth. 