1)I sailed my u-boat into a harbor named Grimsby in my first patrol, found 5 docked tankers. But 2 of them disappeared just after loading savegame, 1 of them warped to other position overlapping another tanker.
(refer to following piture)
2)In "SUB SYSTEMS Command Room"(key:H), a description says:"ATTACK/OBSERVATION PERISCOPE Magnifications: 1.5(high power) 6(low power), Angular Field: 38°(high power) 9°(low power)". But both periscopes' magnification are not 1.5/6 in game, and the degrees shown in TAI are not 38°/9°.
3)Radioman has a ability named "Direction Finder - Radio". It seems to be a null ability?