LCDR J. M. Alliston, RN, assumed command of HMAS WARRAMUNGA, (destroyer), at sea, relieving CMDR N. A. MacKinnon, RAN, who was taken seriously ill. 1963 A sub lieutenant and four midshipmen were drowned when a whaler from HMAS SYDNEY, (aircraft carrier), was swamped off Hayman Island, in the Great Barrier Reef.