@Mush Martin - You are very close. Valetta harbour is spot on! and you got the class right. Accoring to the page where I found them they are HMAS Ottway and Oxley in Valetta Harbour in 1926.
http://www.museum.wa.gov.au/collecti...otwayoxley.asp
the site has a good Maritime history section with a dedicated RAN Submarine Heritage site which I'm going to add as a research link in the research thread for SHIII mods.
Western Australian Museum Maritime history collection:
http://www.museum.wa.gov.au/collecti...e/maritime.asp
Western Australian Museum Submarine Heritage collection:
http://www.museum.wa.gov.au/collecti...neheritage.asp
This site has some rare stuff I've not seen before plus a page listing all the submarines based in Fremantle during WWII. A must for the SHIV crew!