Deidre was the fifth tropical cyclone of the 1973-74 season and the third to develop in the vicinity of Cocos Island. At no time did it cross land but during its developing stage the cyclone passed within 25 km of Cocos Island. Deidre moved generally westsouthwestward and was located west of 80°E by 26 December where it was renamed Dalida by the Mauritius Meteorological Service. The system was approaching maturity as it moved out of the Northwest Australian Region. No damage attributable to cyclone Deidre was reported by Cocos Island or ships at sea.
For more details see the TC Deidre Report (pdf).