Stepanek stepping up to save the day when the boat was taking on water.
Dodge's message to the Orlando acknowledging their firing solution and the 'destruction' of the Stingray. Then he adds that he launched his torpedoes just before they locked on target, so he wins the wargame when the target ship explodes gloriously in the harbor.
How the Stingray managed to sneak into the harbor: they hid the submarine in the SONAR blind spot created by a freighter's engines, allowing them to sneak right past the entire fleet that was hunting them. Which by the way would totally work in real life.
While it would be easy to say "Every crazy scheme they tried that worked," Stepanek's saving of the engine room when it starts taking on water takes the cake for individuality. First he gives a (VERY brief) Rousing Speech to the crew that wants to abandon, then when it looks at first they have things under control, the Main breaks and is twice as bad as all the rest put together. Stepanek picks up a brace and single-handedly charges straight against the geyser to clamp it down.
Stepanek not screwing the rest of the crew when they were in Silent Running Mode, saying that it would be unethical despite being the quickest and easiest way to achieve his stated goal of getting reassigned from submarine duty.