Question: HMAS "Platypus" was a submarine depot ship and base ship operated by the Royal Australian Navy (RAN), ordered prior to World War I to support the Australian submarines originally known as just AE1, HMAS "AE1, was an "E"-class submarine of which organization?
Sentence (from "HMAS AE1"): She was the first submarine to serve in the RAN, and was lost at sea with all hands near East New Britain, Papua New Guinea, on 14 September 1914, after less than seven months in service.
Relevant evidence: No