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

[frau kaleun]

Originally Posted by Akela

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?

If they have passive sonar (the equivalent of your hydrophones) that will pick up sounds from a submerged vessel - then I'm going to say, yeah, that will make enough noise for them to pick it up.

Also I don't remember offhand how deep the water is in and around Scapa Flow, is it possible you entered an area too shallow for your 40 m depth and grounded the boat on the sea floor and took damage that way?

[Falkirion]

Agree with what Frau said. The waters around Scapa are fairly shallow so you might've been scraping the bottom.

I spend most of my time on the surface so far as late as 1940, and that was 12 patrols in on my last career. Your watch crew should alert you to anything if you stay up there, then its an easy case of crash diving if a hostile DD comes your way.

Others can probably advise on the best time to remain submerged during the day later in the war, but early on being on the surface beats submerging for the day hands down.

[Hinrich Schwab]

Like everyone says, Scapa Flow is very shallow. Once you get past the shore batteries (assuming you are approaching the harbor), one or two meters make a difference in whether you are scraping the bottom or not. You cannot rely on the simple dive and periscope depth commands as you have a high chance of bottoming your boat.

Scapa Flow is heavily defended with competent destroyers with good sonar. Here are some tips to get through.

1. Order Silent Running
(this kind of goes without saying)

2. NEVER go faster than Ahead Slow/Kleine Fahrt Voraus
(If you have not been detected or pinged, you can risk Ahead 1/3 IF you turn on your grammophone beforehand to confuse the destroyers. The other advantage is you have roughly 8-9 hours of charge on the batteries at this slow a speed versus 30 minutes at Ahead Flank.)

3. Keep an eye on your crew and rotate out fatigued crewmembers.
(Tired crewmembers, the ones with red exclamation points next to them, make noise. One tired crewman can mark your boat. Believe me.)

4. Keep your periscopes down. Raise them only if you need to.

I have run through Scapa Flow in most of the game's boats ( I refuse to use Type IIs) Following these tips should help you out.

[HW3]

You might have hit a mine. I doubt it was the bottom since all your damage is top side. Very unusual that TC didn't drop to 1 but, I had the same thing happen while swinging around the SE corner of Helgoland in a type II. All sorts of damage reports, flooding, ect, and yet TC stayed at 8 where I was running at the time.

[Alpha Von Burg]

I would agree with HW3, it is unlikly that you hit bottom because your damage was top side.

However, the waters around Scapa Flow are indeed very shallow and it is not possible to dive at a depth of 40m, let a lone beyond 25m.

From your statement, I would say it was a mine because if it were a surface vessel, you would be hearing a lot of pings, because after the fist vessel pings you, more would follow, especially in an area like Scapa Flow.

I would also say that that was a close call, because that mine could have been closer.

Good Hunting...

[Akela]

Thank you all for the advice. It wasn't the bottom though, I forgot to mention that I was rapidly spamming the depth report button the whole time and the lowest that it ever reported was an additional 25 meters. I wasn't trying to enter the Scapa Flow harbor, just pass through the strait that is south of it, hugging the Scottish coast.

Also, I mis-reported my speed, which was ahead slow, not 1/3rd.

But based on everything you guys came up I think it's most likely that they just heard me. I hadn't rigged for silent running (since I wasn't repairing I thought that wouldn't make any difference). Also, I was in a Type II.

Second best guess is I hit a mine. Didn't know there were mines there. Heck, didn't know there were mines anywhere. I learn something new every day here. Thanks!

I'm going to make another run at it right now and see what happens!

Cheers,

Akela

[Pisces]

Originally Posted by Akela

...

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.

...

So you crossed the gap between AN15 and AN16? I would prefer the gap in AN14, less shallow and not so much a detour. AN15/16 is heavily patrolled. You could easily have been too close to them to get above their hydrophone detection level (at 1/3rd throttle). And then followed up with active sonar. There just isn't much room to avoid them. I don't always get a crew report about getting DC-ed or pinged. So it's not a guarantee that you'll be safe in the absence of those reports. Also since all the damage is topside it definitely hints to depthcharges.