How did they find me?

[Akela]

I need to learn how to be...well...sneakier. I am on my second career and my 3rd wartime patrol, which should give you a pretty good idea how my first career went. I had just finished my 24 hours in AN18 with all my torpedoes and a pretty full tank of gas so I decided to sight see on the other side of the British Isles. I plotted a fairly straight-forward course around the north side of the Isles.

So, as you probably know, there is a strait between the mainland of Scotland and a group of islands that is home to a hostile port called "Scapa Flow". I am aware that the area is a fairly difficult one but I had the theory that I should be able to go anywhere as long as I stay submerged during the day and only surface at night to recharge, etc. It's September of 1939, so just the very first days of the war.

Anyway, about 05:00 I dive to 40 meters, set my speed to one-third and start cruising towards the entrance of the strait (at 128tc) After a little while I notice that I'm taking some damage. I'm a bit surprised that damage does not cause my TC to drop to 1 but it doesn't. I get the clock down to 1 and notice that about 15 minutes has gone by since the first damage message.

So there is no mention in the messages about being pinged, about depth charges in the water or anything like that. Just three damage messages, Radio Antenna, Observation Periscope, and Attack Periscope. That was all at 12:10, now it's 12:25.

After a few seconds I hear some pinging. Still no alert from anyone that I'm being pinged, but a ship drives right over the top of me pinging like crazy. No notice about dc's in the water but there are some explosions and the screen shakes although the sub doesn't appear to take any further damage. I immediately called for silent running, dived to 40 meters or so, set my speed to 1kts and turned around. The ship passed over me 2 or 3 times again but never dropped any more depth charges.

Now it's 13:06 and I've moved a ways south. Occasionally I still hear pinging from the north but they are only for brief moments and it's pretty far away.

So, given that background, here are the things I am wondering:

1) Where did that original damage come from? Did that warship drop some depth charges on me? If so, is it normal for the tc to stay at 128 when that happens? Is it possible something else caused the damage and the warship heard it and closed on me during the 15 minutes between when the damage occurred and when I got the tc down to 1 and heard his pings?

2) If the warship did cause the original damage how did he find me? Am I making enough noise at 40m on 1/3rd to alert ships around me?

3) If the answer to 2 is yes, how the hell can I sneak through that strait?

4) Or am I just being stupid and should take the long way around and realize that I'm just not as invisible as I think I am?

5) Oh, and finally, is my Sonar man a deaf-mute, or merely deaf?

As always, thanks for your help,

Akela