Lookouts or Hydrophones?

[DrZaius]

Hi all,

I have returned from a brief hiatus to hunt the North Atlantic once more. I just installed GWX for the first time, so I am trying out the mod and seeing how I need to adjust from the stock game. My question pertains to how to detect ships.

For the most part, if I get a map contact I bird dog it and hunt it down fairly effectively. My question is: Does it make more sense to wait on the surface, or hover around periscope depth and listen on the hydrophones? Which is more effective?

Obviously, this is highly dependent on weather. Let's presume for sake of argument the weather is great for visual spotting (Clear, etc.). Am I going to do better with my lookouts on the bridge, or waiting underwater for them to show up using my sound detection?

Followup, related question: For general hunting (i.e. when I don't have a report to chase down), my hunting method has been to cruise very slowly in high traffic areas during the day at periscope depth, then surface at night to recharge my batteries. I tend to stay surfaced the majority of the night (even though my batteries and air have been replenished rather quickly). Is this a sound hunting method, or should I adjust it?

Thanks!
-DrZ

[maillemaker]

I personally always try to hunt using visual contact. It's far to slow to try to intercept submerged.

Steve

[Aras]

Most of the time I look up for enemy vessels surfaced. If the weather is bad with low visibility I make regular hydrophone checks for 1-2 hours. If a contact is detected with the hydrophone then I surface and cruise with high speed.

[Leandros]

Originally Posted by DrZaius

Hi all,

I have returned from a brief hiatus to hunt the North Atlantic once more. I just installed GWX for the first time, so I am trying out the mod and seeing how I need to adjust from the stock game. My question pertains to how to detect ships.

For the most part, if I get a map contact I bird dog it and hunt it down fairly effectively. My question is: Does it make more sense to wait on the surface, or hover around periscope depth and listen on the hydrophones? Which is more effective?

Obviously, this is highly dependent on weather. Let's presume for sake of argument the weather is great for visual spotting (Clear, etc.). Am I going to do better with my lookouts on the bridge, or waiting underwater for them to show up using my sound detection?

Followup, related question: For general hunting (i.e. when I don't have a report to chase down), my hunting method has been to cruise very slowly in high traffic areas during the day at periscope depth, then surface at night to recharge my batteries. I tend to stay surfaced the majority of the night (even though my batteries and air have been replenished rather quickly). Is this a sound hunting method, or should I adjust it?

Thanks!
-DrZ

As your passive sonar has a much better range than your visual I'd say the obvious answer to your question is to stay below as much as possible - even more so when it is dark. You can still receive position reports when submerged.

When you have obtained contact is the time to surface to intercept the target after first having calculated its general course.

Just my opinion.

Regds

Fred

[Pisces]

Observation crew can report upto 8km or 16km (depending on mod installed, i.e. GWX) Hydrophone crew reports upto 20km or so. But listening yourself in the hydrophone station gets you bearings from upto 34km. So the effort of doing it yourself, ever so often as desired, is well payed. But it's still mind-numbingly boring. And you can't stay submerged ( below 10m) for ever. The ocean is a really big place, so don't expect to find anything in one spot. Move across an expected traffic route for better chances, or position yourself in a chokepoint.

[DrZaius]

Originally Posted by Pisces

Observation crew can report upto 8km or 16km (depending on mod installed, i.e. GWX) Hydrophone crew reports upto 20km or so. But listening yourself in the hydrophone station gets you bearings from upto 34km. So the effort of doing it yourself, ever so often as desired, is well payed. But it's still mind-numbingly boring. And you can't stay submerged ( below 10m) for ever. The ocean is a really big place, so don't expect to find anything in one spot. Move across an expected traffic route for better chances, or position yourself in a chokepoint.

Even with the extended range of the hydrophones, it seems like I would have a better shot on the surface. Submerged, I can cruise at let's say 4 knots. On the surface I could do 12. That covers a lot more total area. The question becomes if it's better to cover more area, or a smaller area more effectively.

Edit: I presume my effective visual range is shorter at night. Also, cruising on the surface during the day leads to its own troubles, ie airplanes. It's an interesting problem.

[Sephiroth]

I normally use the surface at lower speeds. If I get a report and am attempting to intercept I will begin regular dives when getting close to pin-point the location and direction of a convoy, but normally close on the surface until it is unsafe to do so. I do get close by running about 7m (decks awash) since it makes it harder for the enemy to see just my con.

[Kielhauler1961]

I use the same methods as Leandros and Pisces. proceed to a hot-spot area and submerge.

I tweak the speed to 80 revolutions (<1 knot) and go to x64 TC.

Following a short plotted course at 45 degrees to the likely track of traffic, I alter course every 15-20 minutes by up to 90 degrees either side of my mean course to open the hydrophone arcs and catch anything sneaking through the dead zones ahead and astern.

I check the hydrophones myself at least once an hour, normally more and yes, it is tedious but you will catch sounds the crewman won't.

Same when the boat is surfaced to recharge batteries between dips. I scan the horizon myself and have spotted targets out as far as 18.5km on a good day. Having a high definition monitor helps.

It all depends how much effort you want to put in. Unless 'warping' between hunting grounds I cruise at slow speed and never more than x64, frequently less. My patrols take longer to complete now but I catch a lot more fish this way than I used to.

KH

[Pisces]

Originally Posted by DrZaius

Even with the extended range of the hydrophones, it seems like I would have a better shot on the surface. Submerged, I can cruise at let's say 4 knots. On the surface I could do 12. That covers a lot more total area. The question becomes if it's better to cover more area, or a smaller area more effectively.

Edit: I presume my effective visual range is shorter at night. Also, cruising on the surface during the day leads to its own troubles, ie airplanes. It's an interesting problem.

Well, you don't have to stay submerged the whole time. Just dive long enough for your ears to adjust to the quietness and scan your surroundings. After that you can move and dive at a different location.

The question is in which direction to move, at what speed, and in which interval do you dive-check again. If you move in the same direction of expected enemy trafic, and with similar speed, then the other units still out of range will barely get a chance to enter your sensor area. If you go against the expected traffic direction, then the relative speed between you might be so great that you miss him leaving your sensor area before your next dive. If you move across the expected traffic direction then his speed determines the interval, and gives you more chance of catching a contact in a wider traffic lane. But it still primarily a game of chance and patience.

I did some general calculations some years ago about which interval would be prudent, considering the relative speeds, and how visual compares to hydrophone.

http://www.subsim.com/radioroom/show...27#post1021427

p.s. High timecompression is detrimental. It makes the contacts outside of your area jump with bigger leaps through the world. If really high the jumps are large enough to either skip your region entirely, or make them materialize at point blank range. Not good if they have DD friends with them. Airplanes are much faster, so it is more apparent with them at lower timecompression levels. Either they don't seem to be there, or they are already circling your burial-at-sea.

[DrZaius]

Originally Posted by Pisces

p.s. High timecompression is detrimental. It makes the contacts outside of your area jump with bigger leaps through the world. If really high the jumps are large enough to either skip your region entirely, or make them materialize at point blank range. Not good if they have DD friends with them. Airplanes are much faster, so it is more apparent with them at lower timecompression levels. Either they don't seem to be there, or they are already circling your burial-at-sea.

Great, informative post. In particular this last part was something that I think I knew before, but had somehow forgotten in my absence. I loaded up the game this time around and thought to myself, "Time Compression goes up to 4096? Why was I mucking around at 512 all that time?..." Very handy to know this bit about TC affecting your chance of running into an enemy ship.

[Andrewsdad]

Salute !!!

Another consideration is that in mid to late 1942 the Allies will start having radar on some aircraft and you will not yet have METOX. So running surfaced at night in relatively clear weather can be very dangerous.

AD

[UKönig]

Personally, I have found that both systems have their uses.
Dive and listen when the weather is bad or at night. Or if you suspect there are ships in the area. Sometimes I go to sneak travel "schleiss fahrt" and then listen, other times, all stop to be extra quiet.
I try to do all my intercepting on the surface. One thing we all forget is that a U-boat is less of a submarine and more of a torpedo attack boat that has the ability to dive.
Best bet is to have at least 3 watch trained crew, preferably 1 officer and 2 POs and 2 standard crew. If you have only standard crew (lackies, minions) then odds are good that they will miss something important. I have also had them fail to inform me of 'schiff gesicht' in time (heavy fog), and a collision was the result.

[Pisces]

Originally Posted by UKönig

...Sometimes I go to sneak travel "schleiss fahrt" ...

"schleich fahrt" soft 'g'

[banryu79]

I have recently return to Wilhelmhavens after completition of my very first patrol (1939). My assigned grid patrol was BF13, around the western approaches (I was lucky).

My patrol strategy was this:
- I defined a "patrol box" of about 200x90 Km centered on my patrol zone.
- I defined a saw-like "patrol course" with many waypoints.
- The saw-like patrol course was left-to-right or right-to-left depending on what my current location was with respect to the patrol zone itself (i.e. if I was on the right side I plotted a right-to-left oriented patrol course).
- The course was made of vertical legs alternated with diagonal ones.
- Each diagonal leg spanned along 25 Km in the horizontal direction with respect to the patrol box defined.
- I marked 3 equidistant spots along each diagonal leg; 2 along the vertical ones.
- The sposts on the diag and vertical legs were choosen in a way that maximized the area covered (I did try to not overlap them much).
- At each of the 3 spots on the diag leg I go to 30/20m deep and run silent for 2 hours.
- At each of the 2 spots on the vertical leg I go to 30/20m deep and run silent for 3 hours.
- When surfaced I run at ahead std till the next spot.
- In the rare case I'm able to compete the whole run without detecting contacts (never happened, in the worst case I have experienced I was able to run almost half of it, in about 2 days or little more) I plot another one in the opposite direction, rinse and repeat.

My patrol ended with 13 ship sunk, 10 of which detected and engaged in 8 days during this exercise.

[BigWalleye]

Trevally has produced an automated script for SH5 which seems to be quite effective. In SH3 terms, it is:

Patrol surfaced for 2 hours at Standard speed. Use whatever search pattern you prefer. (FWIW, I use a 60 degree retiring zigzag.)

Submerge to 30 m (less if shallow!). Slow to 2 kts. Maintain search for 5 minutes.

Go to Standard. Make a clearing turn (90 degrees either side - you pick). Slow to 2 kts. Maintain new heading for 5 minutes.

Go to Standard, surface the boat, and return to course.

(Rinse. Repeat.)

It's not necessary (or IMO, productive) to spend more time than necessary at a speed effective for hydrophone sweep. That just limits your swept area. You can hear out 30 km. That's just under 2 hours cruising at 10 kts. So you will have only a slight gap in your search pattern while covering a swathe 60 km wide. (To eliminate the gap, dive on the even hour instead of every two hours. The time spent at depth will offset the gap.)

If you want to search a wider swathe, remember that targets can pass outside the swept area while you are on the opposite side of the search pattern.