AOD out of the box functions that SH3 didn't have.

[John Pancoast]

I like SH3. But look at the differences out of the box between the two. Crazy that a game made years later didn't have the same at a minimum. Wasn't for modders adding some of these......I won't add atmosphere, etc. as though AOD does better in these gray areas too, I'll just list black/white functions.

1. Abandon boat
2. Varying crash dive times (not just between sub types either).
3. Correct and realistic Allied air power, etc.
4. Accurate damage model.
5. Radio reports that follow the historical timeline that are pertinent to your boat. I.e., don't use radio because of rdf, etc.
6. FIDO torpedo attacks.
7. Wolfpacks. Not only that the player could call in, but they would also send signals to call in the player to a convoy.
8. Accurate convoy and escort group sizes.
9. Realistic sinking/damage.
10. Accurate and helpful hydrophone situational awareness.
11. Challenging, realistic AI. Even with the great work done in the megamods, the SH3 AI pales in comparison.
12. Ability to save the game almost anywhere, anytime.
13. Time compression that can be used at any level without it affecting the game.
14. Convoy evasion tactics; zig-zag, etc. Along with this, escorts that have unpredictable search patterns while escorting.
15. Accurate weapon power.
16. Moonlight affects visibility (still not in SH3).
17. Weather affects ship speeds. Along with this, a weather system that worked.
18. Different depth charge types modeled.
19. Different escort attack types modeled.
20. Affect on boat (leaks, etc.) if running on silent running.
21. Flags, crew, and pennants on your boat.
22. Accurate, working RWR function (still not in SH3).
23. Ships fire flares when hit.
24. A chronometer that is accurate with torpedo impact time estimates.
25. Depth charge explosion effects briefly masks your noise.
26. Milk cows
27. Convoy ship noise could be used to cover your subs submerged noise. (not modeled in SH3).
28. Your sub underwater speed affected your sonar man's ability; to fast, he wouldn't hear anything. Not so in SH3.
29. Your sonar man couldn't detect things with the sub surfaced. (Took Hsie to fix this in SH3. What a silly, basic flaw).
30. Sunset/rise information.
31. Huff-duff.
32. Ability to send radio message from periscope depth as in real life. Still not available in SH3.
33. Much more accurate torpedo failure rates even including the various mods for SH3.
34. Better AI "listening". I.e., if one chooses to do repairs or load torpedoes, it can increase the chance of detection. Not so in SH3.
35. Single ships actually do evasive maneuvers if they spot you vs. the silly snake dance done in SH3.
36. As in real life, close depth charges can result in no damage but can result in displacing the sub's depth up or down.

Off top of head. Probably more; maybe I'll add them as I remember them.