magnum opus is a must have mod.... critical torpedoes it is not in magnum opus... irai is at version 0.30 now... in short time we will have version 1.0 ... in my opinion irai is the brain of sh5... in magnum opus you have a lot of mods that are like patches... in meantime moders made a lot of nice mods that you can add after magnum opus
the hydrophone is ok now and is quite realistic in my opinion... you can make settings in the option.py(if you will use tdw intreface) or in main.cfg file (from mydocuments/sh5) and your tc will drop at 1 when you will be at some distance from ships, land etc... search this link from here to see what mods people use to play sh5 right now... but the mods are changing very fast also... so keep an eye all the time on the workshop section
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http://www.subsim.com/radioroom/showthread.php?t=173193