Most likely not 'historical'. Brisbane and Fremantle were both SoWesPac, and Brisbane did start going further west after Guadalcanal let up in early 1943, but the Gulf of Siam after mid-1942 would have been probably under British control, and the Gulf of Tonkin would have been quite a haul. Especially if you don't stop at Darwin (if available) or somewhere enroute to top-off the tanks. Part of the problem stems from the old generic Stock boat assignments, which follow the boats, passed to TMO, passed to FOTRS, passed to FotRSU. An update of mission assignments is planned in the future, with a better delineation between SoWesPac and CenPac assignments. From Brisbane, after Guadalcanal, you would move up the chain to the Bismarcks and then on to assignments in the Philippines, maybe the Mariannas or Gilberts, if enroute to Pearl for an overhaul. As for the Yellow Sea area, that was avoided during the war until later, when it became necessary to go in there to find the remaining targets. It is too shallow for "safe" submarine operations. If would fall under the direction of Pearl, until in 1945 when Subic would have it, late.
