map updates

[ralphnader23]

I turned map updates off for the first time, and it was a really rough patrol. Does anyone have some tips for intercepting convoys when the hydrophones don't show the lines anymore?

I got parked in front of a convoy, but then it turn 90 degrees on it's zig zag pattern. I was going parallel to it, waiting for it to turn back on it's original heading, going to periscope depth about every 5 km to see if the heading changed.

For awhile it was consistently 70 degrees, then I finally got an few reports of 85 or 90, closing, long range. Then I got a few more reports of ships at 60 degrees and closing. I figured those were on the far side of the convoy, so I surfaced again, and moved up a couple km, to hopefully get me closer to the convoy path.

Went back to periscope depth, and stopped the engines to wait. The convoy is getting closer, mostly reporting around 90 degrees after 10-15 minutes, but they are still at long range. Then the dreaded report comes; "Enemy is pinging us sir". I pop the periscope up and a frigate is right on top of me, so I crash dive and still take lots of damage.

I guess they heard me when I was surfacing and diving, and managed to pinpoint my position well enough to sonar me? Are there any other good techniques for getting in front of a convoy, especially if you don't know it's exact heading?

Also...when I see a ship with my periscope, should it still appear on the navigation map?

[Sailor Steve]

A good compromise is the Assisted Plotting mod. A description of how it works in included with the download page:
http://www.subsim.com/radioroom/downloads.php?do=file&id=1328

[Pisces]

You seem to keep an eye on bearing only. Meaning at which direction they are from your uboat. That's tricky, since you can't tell if they close up on you or they extend from you. The crew reports of closing or moving away are not totally to be trusted. It just seems to rely on AOB, and not the actual speed and course of you both that make it happen. But above all it's crude. Try to make visual contact and keep at maximum range (easiest in the dark, be very carefull in daylight). Plot the positions of at least one unit. Since you are a beginner I suggest you ask and listen to your watch officer for range and bearings. :know: Until you know how to get reliable measurements with the periscope and uzo.

Merchants move steadily (until they have seen you then it's less steadily but still nothing to worry about, ... yet then the DDs will also know about you making shells starting to hit 'the fan' and you, so that's something to worry about and avoid at all costs) so these are good candidates. However, there are usually DDs around to protect them so you may not get close until nightfall. DDs have irregular courses as they try to be in more places than one around the convoy. So you have to keep a constant eye on them as they approach and make aggressive course changes to avoid if they head in your direction. You can plot DDs too. You should find some pattern in their movements after a while. The watchofficer can only keep track of the closest unit. And you can't really tell when he decides to switch. So you need to know which unit is the next likely in the vicininty.

Build your situational awareness first by looking at them and if possible make accurate plots. Do not close until nightfall.

[ralphnader23]

How close is too close at night on the surface? What is a good running speed if I am on the surfacing trying to get into position? Will the destroyers pick me up if I run at flank surfaced?

[Pisces]

How close is too close at night on the surface? What is a good running speed if I am on the surfacing trying to get into position? Will the destroyers pick me up if I run at flank surfaced?Flank is ok in my experience to overhaul. I want to get it over with ASAP. But you might choose whatever you need to get into the night:

(current distance behind convoy+ desired distance ahead of convoy)/time until dark + convoy speed=overhauling speed

The trick is to find the right course that doesn't make you get too close. Or loose sight of them too quickly. I usually use this intercept/manouvering drawing to determine that course: (it might be a bit too complicated, I'm sorry)

http://www.subsim.com/radioroom/showthread.php?p=1211811&posted=1#post1211811

Since bearings change very quickly as you get near to your target I generally try to slow down a little, a few knots above their speed. But after I fire my torpedo (sometimes still surfaced to the side of the convoy) I usually set to flank and move directly away as quickly as possible. So far the noise hasn't blown my cover (in 1940) from a kilometer away. I love it when hell brakes loose as the torpedo's hit steel and they have no idea where I am, watching the show of light beams. :arrgh!:

The distance of being too close is indicated when you are targeted and hear bullets wizzing by. Then it is time to dive ASAP. I have no clear number for that. Also depends on light level. Experience grows on you. Besides it is dependent on improvements of Allied quality over the years. I might be lucky now, (well not last patrol :x RIP ) but do need to be careful in the future. If you feel brave and daring then you are too close!