The ultra messages in RSRDC are a great addition. In my current career with the P-class
USS Pike(SS-173)out of Manila I've yet to sink any merchants, but partially thanks to ultra we're now a warship killer. 1st patrol we "only" got the Chitose(a seaplance tender), plus two escorts from another invasion convoy. After reporting the convoy we were told to attack the escorts, so that's what we did. 2nd patrol we were patrolling the South China Sea, when Ultra alrerted us that Heavy IJN units were moving out of Camranh Bay, and were expected to be quite close to us the next evening at 1800 hours. We were in position four hours before Ultra's predicted time, and submerged to listen and wait. At about 1900 hours multiple heavy and light warship screws were heard north of us, and after a while an IJN Task Force appeared. We greeted them with all of our 16 torpedoes, scoring a Shokaku fleet carrier and two Takao-class Heavy cruisers. One attack was made submerged and three on the surface. 3rd patrol the base was moved to Surabaya, and we spotted two unescorted Takaos just 500 kilometers out of the base. Needless to say these found their way to Davy Jones' locker, but it took the whole night and all the 16 torpedoes(gotta love the reliability of torpedos in RFB). Looking forward to the fourth patrol and the first merchant kill, since that's all the four Takaos ever built
