Silent Hunter 3 definitely was! It was ridiculous in 1944. If you were lucky, you got away from Great Britain and into open sea. If you were even luckier, you'd not stumble upon a Hunter Killer group (think 5-6 destroyers with the sole task of patrolling sea lanes for submarines....though you'd usually only encounter them near land, and therefore near airbases). If you were super lucky, any convoy escorts would not be armed with Hedgehogs (an awesome forward firing ASW weapon that only explodes on impact, so they can keep ASDIC scope on you the entire time), and if you were super duper mega lucky...you'd find a solo ship.
It was fun dodging depth charge run after depth charge run when 80 m below sea level spamming decoys and trying to get below the thermal layer that reflects ASDIC back. I had some encounters last 30 minutes to an hour just trying to get deep and lose the hunters. Few things are more ominous than the "ping" you hear. YOu just pray they don't hear it back :D