Bigboywooly - thanks for that, sounds obvious but I had missed that one completely!
Probably sounds daft to the old timers but I've taken to writing myself a check list which I run through before each engagement...It goes soemthing like this
1.Check Nationality - you might laugh but I've sunk too many neutrals in my time!
2.Check Crew in correct compartment - again I've fired off torps with no crew
3.Check Torp settings - depth,speed,spread etc etc
4.Open tube doors - thanks to Bigboywooly for that one
5.Final check for incoming warships -had several slap-downs after forgetting this one.
Have I missed any? probably but its all in the fun of learning.
Happy Hunting.