Periscope depth avoidance

Pat42 · 12-07-07, 06:49 PM

Ive heard (I think from the Ubisoft manual) that being around periscope depth is an effective way so avoid sonar detection because the waves create disturbances. Is this true?
Thanks

Blacklight · 12-07-07, 07:03 PM

Under certain circumstances maybe, but also be aware that at that shallow depth, you may be visible to aircraft or to nearby ships as your siluette may still be visible under the water.. also.. if the seas are rough, your conning tower can be occasionally exposed where an enemy ship can sight it. I prefer to run deep and silent when possible and pull tricks like aim my boat directly at the enemy ships, go under them and run like hell while they're facing the opposite direction.

I have much better luck down deep, silent, and keeping a narrow profile to my persuers to the best of my ability.

Pat42 · 12-07-07, 07:41 PM

That makes a lot more sense, just wondering because one time I got stuck in shallow waters with some destroyers so I couldnt run deep. I was killed easily, I guess the best way to avoid shallow water detection is to point the bow or stern at the boat and run as deep as possible. Or is there another way... :hmm:

3Jane · 12-07-07, 07:54 PM

Rough seas will help you avoid being detected anyway, the destroyers/escorts have a much harder time finding you in those conditions which means under some circumstances especially at PD you can run at a faster speed to assist maneuvering and depth keeping. Personaly I have never been attacked by aircraft whilst running at PD, but I have only survived to 10-41 so far so the later war years may be different.

Pat42 · 12-07-07, 08:00 PM

Yes, and I have done that, I guess if you get stuck in the situation I stated above with clear weather though, you are probably going to die if the detect you.

johnno74 · 12-07-07, 11:41 PM

Its funny this thread has just been started, I was going to start one myself.

I just emptied my torpedo load in a large convoy just north of ireland. Unfortunately they were mainly small freighters, tramp steamers, etc etc (and one southhampton class cruiser - she wore my first two eels!)

I remained just below PD - about 18m, with my periscope down and at silent running. I tried to keep my stern pointed at the closest swan, and they never found me. There was lots of pinging, and some depth charges but none closer than about 200m. When they were far enough away I would line up on another merchant, fire then resume my evasion.

The weather was pretty rough which no doubt contributed, but I held my nerve and stayed shallow even when the escorts passed very close, and although there was plenty of pinging they never made my position

jazman · 12-08-07, 12:37 AM

Quote:

Originally Posted by Pat42

That makes a lot more sense, just wondering because one time I got stuck in shallow waters with some destroyers so I couldnt run deep. I was killed easily, I guess the best way to avoid shallow water detection is to point the bow or stern at the boat and run as deep as possible. Or is there another way... :hmm:

Stay out of shallow water?

Pat42 · 12-08-07, 02:14 PM

That would make things to easy.

PavelKirilovich · 12-08-07, 04:42 PM

In 1942 I recall playing "tag" with a number of destroyers as I was worming my way into Loch Ewes. Running at periscope depth on standard propulsion (IE: Not running silent) at one third speed caused them to pick up on me only when they came within ~500m. At 1/3rd it is a joke to rattle back to silent running if they get about a kilometer off according to your hydrophone operator.

This allowed me to get into Loch Ewes, torpedo an escort carrier and a cruiser, sink a T3, and leave - and I was being pinged constantly but the destroyers never made attack runs as I did this all at PD.

Then I got jumped by the RAF while recharging batteries at night on a glass-smooth sea. Decided to fight them with the Flak guns. Didn't go so hot. Crash-dove and then spent the remainder of my patrol popping up for about an hour each night to try and air out my boat and recharge batteries before having to submerge again and creep along at ahead slow to conserve battery power.

Brag · 12-08-07, 05:15 PM

Once they know I'm there, I go deep.

sasquatch · 12-10-07, 09:38 AM

I'll throw in my two cents for good measure. These results are based purely on my subjective experience of "vanilla" SHIII.

a) no wind + bright day = being spotted at pd by dd's and merchants alike. Have never been spotted by planes.
b) light wind + bright day = being spotted at pd when within 200 meters of enemy vessel.
c) Rough seas = if anything will give you away it will be your conning tower. Set your depth about 2-3 meters below pd. I have never been detected by enemy dd's at this depth on rough seas; even at 6 nots.

12-07-07, 06:49 PM	#1
Pat42 Watch Join Date: Nov 2007 Posts: 30 Downloads: 61 Uploads: 0	Periscope depth avoidance Ive heard (I think from the Ubisoft manual) that being around periscope depth is an effective way so avoid sonar detection because the waves create disturbances. Is this true? Thanks

12-07-07, 07:03 PM	#2
Blacklight Ocean Warrior Join Date: Sep 2006 Location: Connecticut Posts: 2,507 Downloads: 145 Uploads: 0	Under certain circumstances maybe, but also be aware that at that shallow depth, you may be visible to aircraft or to nearby ships as your siluette may still be visible under the water.. also.. if the seas are rough, your conning tower can be occasionally exposed where an enemy ship can sight it. I prefer to run deep and silent when possible and pull tricks like aim my boat directly at the enemy ships, go under them and run like hell while they're facing the opposite direction. I have much better luck down deep, silent, and keeping a narrow profile to my persuers to the best of my ability. __________________ Be my friend or be a mushroom cloud. "I am coming at you. You will explode in a couple of minutes !"

12-07-07, 07:54 PM	#4
3Jane Ace of the Deep Join Date: Sep 2006 Location: York. Northern England. Posts: 1,004 Downloads: 0 Uploads: 0	Rough seas will help you avoid being detected anyway, the destroyers/escorts have a much harder time finding you in those conditions which means under some circumstances especially at PD you can run at a faster speed to assist maneuvering and depth keeping. Personaly I have never been attacked by aircraft whilst running at PD, but I have only survived to 10-41 so far so the later war years may be different. __________________ Fate opposes me in vitality and morality, forced ever onward, burdened, always in shackles. So this very moment, without tarrying, pluck the quivering strings. Because fate punishes the one who plays, all lament with me. (http://hosted.filefront.com/KatherineRowan)

12-07-07, 11:41 PM	#6
johnno74 Planesman Join Date: Nov 2006 Location: Melbourne, Australia Posts: 197 Downloads: 5 Uploads: 0	Its funny this thread has just been started, I was going to start one myself. I just emptied my torpedo load in a large convoy just north of ireland. Unfortunately they were mainly small freighters, tramp steamers, etc etc (and one southhampton class cruiser - she wore my first two eels!) I remained just below PD - about 18m, with my periscope down and at silent running. I tried to keep my stern pointed at the closest swan, and they never found me. There was lots of pinging, and some depth charges but none closer than about 200m. When they were far enough away I would line up on another merchant, fire then resume my evasion. The weather was pretty rough which no doubt contributed, but I held my nerve and stayed shallow even when the escorts passed very close, and although there was plenty of pinging they never made my position __________________ When you pull the pin from Mr. Grenade, he is no longer your friend.

12-08-07, 04:42 PM	#9
PavelKirilovich Machinist's Mate Join Date: Nov 2007 Location: Canadian Coast Posts: 123 Downloads: 28 Uploads: 0	In 1942 I recall playing "tag" with a number of destroyers as I was worming my way into Loch Ewes. Running at periscope depth on standard propulsion (IE: Not running silent) at one third speed caused them to pick up on me only when they came within ~500m. At 1/3rd it is a joke to rattle back to silent running if they get about a kilometer off according to your hydrophone operator. This allowed me to get into Loch Ewes, torpedo an escort carrier and a cruiser, sink a T3, and leave - and I was being pinged constantly but the destroyers never made attack runs as I did this all at PD. Then I got jumped by the RAF while recharging batteries at night on a glass-smooth sea. Decided to fight them with the Flak guns. Didn't go so hot. Crash-dove and then spent the remainder of my patrol popping up for about an hour each night to try and air out my boat and recharge batteries before having to submerge again and creep along at ahead slow to conserve battery power. __________________ Winter Garden on the North Atlantic Currently: U128 (Type IXC), U180 (Type IXD2), U198 (Type IXD2) operating in the I.O. Previously: U48 (Type VIIB), U568 (Type VIIC) [Completed 1940-1945 career in Type VIIs, in the Atlantic] Running: SH3 v1.4b w/ GWX 2.1

12-07-07, 07:41 PM	#3
Pat42 Watch Join Date: Nov 2007 Posts: 30 Downloads: 61 Uploads: 0	That makes a lot more sense, just wondering because one time I got stuck in shallow waters with some destroyers so I couldnt run deep. I was killed easily, I guess the best way to avoid shallow water detection is to point the bow or stern at the boat and run as deep as possible. Or is there another way... :hmm:

12-07-07, 08:00 PM	#5
Pat42 Watch Join Date: Nov 2007 Posts: 30 Downloads: 61 Uploads: 0	Yes, and I have done that, I guess if you get stuck in the situation I stated above with clear weather though, you are probably going to die if the detect you.

12-08-07, 02:14 PM	#8
Pat42 Watch Join Date: Nov 2007 Posts: 30 Downloads: 61 Uploads: 0	That would make things to easy.

12-08-07, 05:15 PM	#10
Brag Navy Seal Join Date: Nov 2006 Location: Docked on a Russian pond Posts: 7,072 Downloads: 2 Uploads: 0	Once they know I'm there, I go deep. __________________ Espionage, adventure, suspense, are just a click away Click here to look inside Brag's book: Amazon.com: Kingmaker: Alexey Braguine: Books Order Kingmaker here: http://www.subsim.com/store.html For Tactics visit:http://www.freewebs.com/kielman/

12-10-07, 09:38 AM	#11
sasquatch Medic Join Date: Nov 2007 Location: Kentucky, USA Posts: 160 Downloads: 0 Uploads: 0	I'll throw in my two cents for good measure. These results are based purely on my subjective experience of "vanilla" SHIII. a) no wind + bright day = being spotted at pd by dd's and merchants alike. Have never been spotted by planes. b) light wind + bright day = being spotted at pd when within 200 meters of enemy vessel. c) Rough seas = if anything will give you away it will be your conning tower. Set your depth about 2-3 meters below pd. I have never been detected by enemy dd's at this depth on rough seas; even at 6 nots.