Yeh, those two are problems in game Fast torpedo 100% always about 36 knots (down from 46) (personally tested along with several others), and the range using Mast is wrong also for several ships as Krupp said (I looked and tested too -darn he is right)

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Since if using the basic TDC Range, Target Speed, and AOB -
both of those problems will affect the hit rate. (it assumes your torpedo is going 46 knots Fast torpedo are bugged as of patch 1.1 fixed in patch 1.2 coming so use slow 31 knots torps).