A question for US Sub Commanders...

[Jack Cutter]

About how I can't get anywhere with all those planes buzzing me overhead! So I have edited my air files in the Silent Hunter 4 directory, in hopes of a few less air contacts. I'm pleased to say it's worked, but there are still air contacts. As far as I can tell, this is pretty realistic, since Japan did have air patrols looking for subs if I remember right. I don't want to mod my game to where there are NO planes, because that would just be very unreal. :down:

Anyways, I've stalked some threads on the forums and the general tactic I notice is diving to at least periscope depth during the day. Now, I'm running two different american campaigns. One in 1942 based out of Freemantle in a Salmon Class sub. The second campaign is based out of Pearl in a Gar class sub also 1942. What I want to know is how does everyone manage to run their subs underwater until nightfall?

I've attempted this and usually end up surfacing to prevent my batteries from draining all the way to nothing...of course I'm running ahead standard while under. Is this my mistake?

Is the general concensus to run ahead slow, or to just shut down the engines and sit idly until the sunsets?

Thanks in advance, Captains....!:salute:
EDIT: I also happen to have a U-Boat campaign running. My first patrol was set to be in the Indian Ocean. I sunk around 23,000 tons of merchant shipping. (7 boats) I was shocked and figured my name would be first on the board considering in my American campaign I sunk around 7,000 tons and was 2nd on the board of aces. I was dead wrong. 23,000 tons of material earned me a 10th place in the German Aces. This is shocking for me...I sunk a lot of Australian merchants. Many sailors and countless dollars of material is somewhere on the bottom of the ocean and I hardly earned a pat on the back...
So, my question is this: Was the German U-Boat theatre (Atlantic/Indian Ocean) really just a huge turkey shoot? Of the 7 vessels I sank none were escorted. Time is 1942. Is this historically accurate? Or is this just a quirk of Silent Hunter 4?

Why is 23,000 tons worthless to the Germans and 7,000 tons is somewhat a decent rank for Americans?

[corsair15]

Air Patrols are unavoidable. You'll run into them everywhere, and they are the most dangerous threat to you. You can alleviate their pressure a bit though. Typical air patrol ranges were about 450 to 500 nautical miles (from smaller bases that have more fighters than long range aircraft). Also, an air patrol will never travel more than half the distance of it's ferry range (maximum range, traveling one-way). Here's what I do:

I go to the map (F3) and start drawing radius circles from all major and minor ports that are in Japanese control. Smaller bases such as (Wake Island, Majuro, Rabaul, etc.) will typically scramble fighter patrols more often than long range aircraft. So I draw a radius circle (Radius Circle Tool) 500nm from those bases, simply because an A6M2-5 Zero has a ferry range of about 1000nm. Therefore, it cannot travel further than 500nm and make it back to base; and I wouldn't expect an air-patrol further than that. I draw radius circles about 1000nm from major ports. So, now that you have your circles drawn, your next decisions depend on a couple of things.

What type of mission are you on? What realism level are you playing at? Do you play "Dead-is-dead?"

I play dead-is-dead all the time. If my sub sinks, I delete the file and start a new campaign. That affects my decisions. So here are some guidelines I use that you might consider.

If I'm on Photo-Recon missions, or Agent insertion missions, I play differently than when I'm on normal patrol.
Try this:



If you pick up Radar Contacts, you should Crash Dive immediately. Make sure you are below 100 feet. Any less, and you're visible from the surface, and therefore an easy target.
After crash diving, decrease speed to Ahead 1/3 and go to the Sonar Station to check for surface contacts. If you find a surface contact on the same bearing as your radar contact, you probably only picked up a naval vessel. Come back to periscope depth and check the bearing for aircraft. You should wait 5 minutes after checking before surfacing (It typically takes 4 and a half minutes after picking up radar contacts before they pass nearby.) If you see nothing, surface and continue with your mission or follow the ship if it's a surface contact.
If the contact is behind you (Between 135 Degrees and 225 Degrees), you should still keep your speed at Ahead 1/3, but turn 90 Degrees to Port or Starboard and check the sonar again before coming back to periscope depth and repeating step 2.
If you spot an aircraft while you are surfaced(sometimes you don't pick them up on radar), you have two options; fight it out and dive after the first attack, or crash drive immediately and go down to maximum operating depth at flank speed. If you spot it at periscope depth, dive immediately (Preferably below 200 Feet just in-case you still get spotted). Return to your original course, increase speed to Ahead 2/3. Wait an hour (time-compress it) and come back to periscope depth, check the sky again, wait 5 minutes; if there's nothing, surface and continue with your mission. I've noticed that it normally takes 45 minutes for the plane to pass by you again on it's return course, but I still wait an hour anyway.
If you're getting buzzed by aircraft more than 4 or 5 times in a two or three hour period, there's probably a carrier nearby. I'll leave it up to you to decide what to do about that one.
If you're inserting into enemy ports, or if you're nearby enemy held territories, you should expect to be buzzed constantly. You should run below 100 feet if possible at about (2 Knots). You can stay at this speed for days without running out of power.
When recharging batteries in enemy territory, you should find a corner to hide in (or somewhere where patrols won't come by) and surface (preferably at night) at a full stop. Wait until recharged, submerge and continue on. If recharging while on patrol or in the middle of large areas of ocean. Recharge at Ahead 1/3 to recharge faster, but under no circumstances should the submarine stop.
In the Early stages of the war (December of 41 to about June of 43) if you pick up Radar contacts at night, they'll almost always be surface contacts. After that, you'll start running into air-patrols at night as well, but even at the early stages of the war, I'd make it a habit to crash-dive anyway. Check the sonar, and decide what to do next.
If you sustain any damage to your propulsion system, hull, or weapons system, return to port. Even if the damage is only 1 percent. Your maximum depth is decreased, and so is your range, and combat effectiveness. Just 1 percent might be the difference between surviving and dying. If you sustain damage in enemy territory, be prepared to give them everything you have (you might die anyway)
If you run into destroyers or subchasers, go to maximum operating depth immediately. Decrease speed to less than 2.5 Knots, and pray. If the escorts get very close to the submarine, as their prop noises get louder, increase your speed. If they're right on top of you, increase to flank. When they start leaving you, decrease speed again.

Stick to those guidelines, and you should survive the entire war. Don't be conservative with the maximum depth of your submarine. I take mine there constantly, and I haven't died yet. It's about 328 feet. I always take mine to 325. Leave nothing to chance. One time I crash dived after spotting an A6M2 Zero about 100 miles west of Midway, at about 225 feet, the unthinkable happened. He hit his mark perfectly, and my submarine was smashed. Nearly 50 percent damage from one strike. Batteries were damaged, Deck Gun damaged, AA Gun sustained some damage but still worked (I had to surface and shoot him down), radar destroyed, control room and bow torpedo room flooding. I limped back to midway, and limped back to pearl right after that. There was no way I could finish the mission. Had I dove to 325, I may have evaded the attack. So don't be conservative with the uses of your submarine. Take it as far as it will go everytime. And plan EVERYTHING.

To answer your question. Running submerged all day while in the middle of the Pacific isn't entirely necessary. You can emerge an hour later and you probably won't run into another contact for a couple of hours. Running submerged all day near enemy territories is entirely necessary. You shouldn't risk running on the surface until nightfall. Like I said, 2 Knots and you should be able to run all day.

As for the U-Boat Add-on. I don't have it, but I do have an answer for you. There were nearly 1,000 U-Boats and only 250 U.S. Submarines, so it isn't surprising that U-Boat tonnages would be higher. There's more submarines, and therefore, more Contact reports. Giving more chances for submarines to attack convoys (Especially the big ones) It only makes sense for U-Boat Captains to have more tonnage on average. They get more reports.

Hope I helped and remember, leave nothing to chance; plan everything.

Thanks for reading,
Corsair15

[Jack Cutter]

WOW! :D:yeah: Thank you so much for that treasure trove of knowledge!

I'm copying and pasting this to a text file and saving it! Its going to be my new reference guide. Absolutely brilliant to mark ranges on the map.

I was surprised at how many air cons I had just 100 or so nautical miles outside of Midway.

I didn't realize how much American subs were outnumbered in comparison to Germany's U-Boats. Now that I know that, it makes a lot more since for the differences in tonnages.

I don't remember if I added this in my original posting or not, but I am only running the stock v1.5 of Silent Hunter 4. Can air cons still spot you while submerged to scope depth in the vanilla version?

Thanks again! :rock::arrgh!:

[tomoose]

I use the range circles also when starting a patrol. You'll have to adjust which bases have enemy aircraft etc as the war progresses. Early war I place a 600nm radius circle centered on Tokyo and the other major cities as well as Iwo Jima.

Another thing to note: you can travel on the surface safely (generally speaking) until you reach the 150E Longitude. That's another "tripwire" I use for myself as to when to be more alert.

I'm not sure I agree with corsair's second bullet point unless he's referring to a sub that has both air and surface radar. If you only have air search radar it won't pick up surface contacts (I've never had that happen). If you get a surface contact you will see it on your surface-search radar therefore it isn't an aircraft and you have more flexibility in how to react.

Air activity depends on whether you are using mods or stock. Stock is notorious for over-the-top air activity and is a royal pain. TMO with RSRD is much better but still some people think the air activity is still too intense. I would argue that it's "intense" because using TC makes the aircraft show up quicker, LOL.

[corsair15]

Good follow up Tomoose. You should check and see if you have both Air Search and Surface Search Radar or not. Air contacts don't show up, so if you just check the radar screen you'll know whether it is a surface contact or not.

If you read all of my post, you'll notice I said sometimes the radar does not pick up the Aerial contact and a watchman will spot it instead. Sometimes your radar does pick it up. Sometimes it picks it up too late though.

It might pick it up right before the watch officers spot it, or it may pick it up at long range, or not at all. Why risk not crash diving to find out? You risk the safety of the entire boat by wasting those precious seconds. I'd crash dive anyway. Why risk it?


And yes, in vanilla version you can still see the submarine down to about 100 feet. Go into your graphic settings and turn on environmental effects. You'll see for yourself.

EDIT: I forgot to mention. You'll recharge batteries fastest at a dead-stop, but it isn't economical to do that during a normal sea patrol. Infact, you should avoid dead-stops if at all possible unless you're waiting for a convoy. That's why I said travel at Ahead 1/3 while recharging on normal patrols. Ahead 2/3 gives good fuel economy when not recharging batteries, plus it's less time constraining when traveling long distances. Any faster and your range starts to decrease. Any slower, and you'll waste more time getting there. I did a test once to see how far I could go at all speed settings. Here's what I came up with:
(These are all approximate)
Ahead 1/3: 15,000nm or 150nm for 1% of Fuel
Ahead 2/3: 11,000nm or 110nm for 1% of Fuel
Ahead Standard: 5,000nm or 50nm
Ahead Full: 4,100nm or 41nm
Ahead Flank: 3,900nm or 39nm (You get the idea, so that's something to keep in mind)
This is for Classes: Gar, Tambor, Gato, Balao, Salmon, Sargo
I plan everything lol, but I don't die either :D
:salute:

[Freiwillige]

Early in the war before radar they ran submerge in daylight hours and ahead slow cause the periscope could leave quite a trail at standard speed and aircraft could still spot the trail from a mile or more.

At Dusk they would surface again.

Once SJ radar was available they would stay up all day because at seven miles it gave enough time to safely get under.

Japan ha no radar equipped fighters so fining you at night was damn near impossible and almost never happened. Edit your air file accordingly:salute:.

[Jack Cutter]

I'll go ahead and edit that. I'm not sure of the values to edit, but I'll take a look anyways. I'm sure I can figure it out.

Thanks again to everyone who posted. I'm always surprised at how quickly I recieve replies to my topics, and how they are always so informative!

Happy hunting, skippers! :salute: :ping:

[Zoomer96]

What ever happened to Anvart's SD Antenna Up Down mod? Is it still available? I dive if an airplane comes within a 8-10 mile radius drawn around my boat and track him at periscope depth with the SD Antenna up to see if he was going to see me (and force me to go deep) or miss me. After he left the 8-10 mile radius circle around my boat I would surface and get back to chasing my target and try to be off his course on his return trip.
I think in WWII if the aircraft was able to sneak up on them, they would dive deep emergency flank speed and make a hard left rudder to dodge the attack.

[Jack Cutter]

EDIT: I forgot to mention. You'll recharge batteries fastest at a dead-stop, but it isn't economical to do that during a normal sea patrol. Infact, you should avoid dead-stops if at all possible unless you're waiting for a convoy. That's why I said travel at Ahead 1/3 while recharging on normal patrols. Ahead 2/3 gives good fuel economy when not recharging batteries, plus it's less time constraining when traveling long distances. Any faster and your range starts to decrease. Any slower, and you'll waste more time getting there. I did a test once to see how far I could go at all speed settings. Here's what I came up with:
(These are all approximate)
Ahead 1/3: 15,000nm or 150nm for 1% of Fuel
Ahead 2/3: 11,000nm or 110nm for 1% of Fuel
Ahead Standard: 5,000nm or 50nm
Ahead Full: 4,100nm or 41nm
Ahead Flank: 3,900nm or 39nm (You get the idea, so that's something to keep in mind)
This is for Classes: Gar, Tambor, Gato, Balao, Salmon, Sargo
I plan everything lol, but I don't die either :D
:salute:

More awesome information!! Thank you so much! I was curious about fuel levels in game. This goes beyond answering my question, and is something else to add to my text files for quick referencing. Thank you!!!! :yeah:

[tomoose]

Zoomer: how can you tell if an aircraft is at 8-10miles? The SD radar doesn't give a range only a bearing.

Corsair; ackd. I haven't had SD fail me yet except when I overuse TC or I decide to wait until a visual is called (usually not a good idea) LOL.

[Zoomer96]

Well, I use the compass tool on the navigation map to draw a circle, a radius, around my boat, centered on the conning tower, and I expand it out until it reads 8 or 10 miles out. Also you can draw a line out to 8 or 10 and then make a circle to that mark. it's sort of cheating. I think the real deal was to use signal strength and eyeballs as a guideline to dive. I move the circle as needed to keep up with the progress of the boat. Remember, once you manage to get ahead of your target dive and move in to within 1000 yards of the target's course for the kill and hope your torpedoes run correctly.