Here's the simplest solution:
Find and open your main game folder - Ubisoft/SilentHunterIII/Data/Cfg/GameplaySettings. If you don't know how yet, you can open them with Notepad. This file holds the different settings for the different levels. The last list at the bottom is [RealismPercentage]. Change all percentage numbers to 0 (zero). Change one you always use (say LimitedBatteriesRealismPercentage) to 99. You can make it 100 but then you won't be able to teleport home if you lose your rudder.
From now on you will recieve full renown for every ship you sink, and you can set the actual skill levels for every parameter except the one you chose for 99% to whatever you like.
And congratulations! You just became a modder.
