Actually, I've fixed the issue with the hydrophone not working correctly. The latest version of the snorkel mod is in my signature. It's still not bug free though. Some people are having issues with the Type IXD2 RWR attaching to the snorkel instead of the submarine. I haven't been able to reproduce the bug myself, so can't fix it for now. Also, the Type XXI seems to get better battery efficiency at 2/3 (or whatever throttle setting 2 is) rather than 1/3 (This bug does not affect the Type IX or Type XVIII). Still working that one out, but alot of the battery based parameters seem like they may be coded into the engine.
Besides those bugs though, it is definately much more playable now that the hydrophone works again...especially since the Type XXI is designed to operate almost entirely underwater where sonar is pretty important.
Oh, and I forgot to change the folder names in the .rar files so it would reflect the current version being Beta 2b and no longer Beta 1. I'll have to fix that issue in case it confuses anyone.