[propbeanie]

@ Comder: Yes, it does - thank you. I had forgotten the Titan... do you remember which submarine it replaced in the Roster by chance?

I do (reasonably) know what happened with the Sargo though in my test mission, and I do not know if the game handles this the same way, but the configuration on the Sargo in the mission was 19380101, and it is not an active submarine until 19390207, but I am reasonably certain that the game does not do that, but only uses the day of origination as the player submarine's configuration date...

@ Mad Mardigan: Are you reasonably certain of the assignment date being 19420124? aka: 24 January, 1942? Does the green circle in my screen grab above reasonably well reflect where your patrol circle was?

Thanks fellows...