The escorts in Silent Hunter 3 use passive and active methods of detecting your U-boat.

Escorts will only search for you without contact for 30-45 minutes. Once they detect your sub the timer will restart. I believe and have been unable to verify that if the convoy gets too far away they will give up the search to catch up with the convoy. Even if the last contact they had with you is under the time limit.

When detected they will alert other ships and aircraft in the area and they will join the search. I do not know the distance but have had other warships and even aircraft showup to join the convoy escorts. This also includes merchant ships. If a unescorted merchant spots you they will radio your position and any nearby enemy will converge on your last known position.

Escorts do not all carry the same equipment. Some may not be equipped with active sonar and carry only one depth charge rack.


Some carry two racks that are deployed by rolling the deoth charges off the stern.
While others carry depth charges that are launched off the stern, able to cover an larger area, as well as stern rack deployed.
Of course later in the war some will be carrying hedge hogs which launch off the bow allowing them to keep contact with the sub at the time of launch. One thing you can be certain of is as the war progresses the more likely you will run into bettter equipped escorts.

Crews of escorts do not have the same compentancy and ability to detect your sub. As the war progresses the more likely you will run into well trained crews.

Escorts and likely equipment they carry maybe added later.

Has farther detection range then active sonar in most cases.

In calm conditions the hydrophone is more effective, important to take in to account when planning your strategy and your ability to evade.

The destroyer is blind aft, directly below, and within about 15 meters of their hull. If you are being hunted by more than one escort the other one(s) will probably be able to hear you.

You are almost impossible to detect on the surface with hydrophones. They will see you before being able to hear you.

The hydrophone gives direction to target, speed estimate, and poor at giving an accurate distance to target. I am not sure but the evidence I have seen suggest this. I have had many escorts dropping depth charges in line with where I used to be when they were unable to actively ping me to get my location. At those times they were able to follow my general direction but missing me by up to 100 meters or more.

This improves as the war progresses. During the early war the maximum distance they can detect you is around 1200 meters out and 200 meters deep. Late war this increases to around 2,000 meters out and 300 meters deep. These are my estimates from trying some things out and the distance may be off 100-500 meters. I am more sure about the depth.

During the early war you may find some escorts do not carry an active sonar. Usually Flower corvettes. Historically before the war passive sonar was considered very adequate to track and locate subs. The Allies quickly learned it was woefully inadequate, could not detect subs on the surface, was rather easy to counter by running silent, and could only get estimated ranges and speed.

The detection area is cone shaped, is shallower as you near the destroyer which is why they lose contact with you on an attack run. The deeper you are the farther away you are from the destroyer when you enter their blind spot.

You are harder to detect bow or stern on with the destroyer. You offer a smaller target for the sonar to reflect off of. This is rather tough to accomplish once they have your location and their is more than one destroyer. It can be accomplished easier prior to them having your exact location by paying attention to your sonar operator or manually do it yourself. I recommend controlling your u-boat from the hydrophone room when being hunted.

As the war progresses the more likely escorts will be equipped with radar. I am unsure of the exact date but you should expect all convoys to have escorts with radar around 1943.

I am unsure about the detection range and will probally verify it later. I have been able to close to about 10,000 meters undetected and have been detected around 15,000 meters out. Rough seas, running decks awash, and profile effect detection ranges.

You may run into escorts equipped with radar prior to being able to equip your u-boat with radar warning equipment.

One way to determine if an escort is equipped with radar is they start heading at you at full speed at very long ranges. The best way is detect them prior to them detecting you with detection equipment available to you later in the war. I find sometimes I can detect them using this equipment before they detect me and others by the time I detect the radar it is too late.

When your periscope is above water it can be detected by radar. You can get an upgrade to make it harder to detect late war. I think the range that it can be detected is at least 1,000 meters.

Aircraft carry radar to detect you in modded versions. I am not sure about vanilla. The good news when you have the radar detection equipment it gives you plenty of warning and more than enough time to dive.

I will make a distinction between modded and vanilla here because I find a big enough difference in how dangerous aircraft are between the two. The mods I am experienced with are GW and NYGM.

In Vanilla aircraft tend to be a nuisance rather than a large threat to your sub. Part of the reason I believe is that your AA gunners are more accurate and able to defend your sub more effectively. I still advise diving and not risk your sub to unnecessary damage and no chance of increasing your tonnage for the patrol. If you want to add aircraft to part of your kills in a patrol I say go for it.

In modded versions go to flank speed and dive and hope you are under before they get in range to fire and drop their bombs.

When you send messages using yoou radio it increases your chance of encountering aircraft. I believe the increased chance is different between mods. This simulates the enemy being able to use radio direction finders and getting a general idea of your location.

I also advise to not to crank up the time compression above 256 when you are in known aircraft operating ranges and on the surface. I find many times above that by the time you get the warning the planes are already lined up and seconds away from firing on you. I think this has to do with the fast speed they travel relative to everything else in the game. I would not worry so much in the vanilla version as the aircraft do not seem to be as deadly.

Attack at night, even if it means tracking the convoy for 12 hours, unless they will be in shallower water by then.

When attacking submerged do not leave your periscope above the water when within 1,500 meters during the day. Raise it periodically to check your target(s) position and get your firing solution but no longer then you need to.

Pay attention to the time of day and the sun and moon. Attacking and approaching a convoy during the day try to use the sun to your advantage. Attack from the east early morning, the west late afternoon and somewhere from the south east to south west in between. During the evening pay attention to the moons location, try to put the moon behind your target(s) when attacking.

I highly suggest attempting all attacks on escorted ships in waters no shallower than 300 meters. Since following this is difficult at times the minimum depths I feel relatively safe is 150 meters during the early war and 250 meters during the late war. This is also highly dependent on the number and type of the escorts. I would feel safe attacking in shallower water if the escort is comprised of only Flower Corvettes.

Run silent, run deep, do not exceed two knots unless avoiding depth charges or you are trying to make a large course change and you are sure they have your position already. Being actively pinged and you are SURE they have your position.

When diving to avoid attack get as much depth as fast as possible. Center your helm, use flank speed if you are pretty sure the enemy has your position.

When your rudder is hard over the turbulance makes enough noise that it maybe heard by nearby escorts. Do not exceed 5 degrees when turning your rudder unless avoiding depth charges or need to make a fast course change for some other reason. Turning hard slows you down, considering how slow you are already moving it can cut your speed by 1/2.

If you are being actively ping that is the time to pick up speed, to prepare to make a course change when they lose contact with you to drop their depth charges. Wait for them to lose contact make your course change, turn hard at flank speed. As soon as your turn is done give the order to run slow and hope that they will not detect you again.

You can dive below your recommended operating range. The depth you can go depends on the condition of your hull. I will leave it to you to figure out how far you can push it. It is kind of thrilling when you are being attacked by 4 or more destroyers you cannot evade and the only option is to try to go deeper than the specs for your sub say you should.

Just because you hear a ping does not mean they have a fix on you. If you start hearing many louder pings you can be sure they know where you are.

Focus on getting out of the search area. Attempting many course changes will keep you in the area longer. Only change course to avoid depth charges, to try to limit your profile for sonar, or put the escorts behind you.

Manually use or pay careful attention to your sonar operator. Try to put the destroyers behind you. It is easier at first until they get a good fix on you. Once they have your position and it is more than two escorts you will most likely be surrounded.

Gain as much intelligence as you can before attacking a convoy. They are slow and easy to remain in contact with once you find them. Come in to around 10,000 meters to determine the number, speed, and direction of travel. This will be a very rough estimate. Then dash ahead to get a better position try to position yourself to be within 4,000-6,500 meters to start picking your targets and get a better idea of number of escorts, speed, direction, and pick your priority targets.

Depending on the situation and how well I positioned myself sometimes I start getting positive ids and maybe start my attack run. If I am not in good position or miscalculated something in my first calculations I dash ahead again. This will be timed to attack early enough in the night that the attack will be completed before sunrise.

Move away as far away from your firing position as you can. Do not hang around to watch if you scored any hits. Once you score your first hit the escorts will be looking for you.

I have had more success getting a good distance from the convoy after firing my first set of torpedoes and then making another attack run after I reloaded and even moved my torpedoes from on deck below. If you get enough distance this will allow you to reload quicker since you will be out of the search area and not have to run silent. During the early war and pre-radar you can surface maneuver ahead to set up for another attack multiple times during the night.

You can use the convoy as cover. Their prop and any sinking ships sounds help mask yours and it is tougher for the escorts to maneuver to drop depth charges. I am unsure how effective the sound masking is, I still find that running above 2 knots the escorts can detect you in most situations. The main benefit I find is the difficulty the escorts have to position to drop DC’s or actively ping you. When in the convoy I fire my remaining torpedoes, usually aft and the one in the bow the crew was able to load, and then dive to run silent and deep.

Deeper than 20 meters is enough to get under ships.

A destroyer's attack run interupted by cargo ship.

Avoid the English Channel, it is shallow, well patroled by ships and aircraft and a high risk low reward area. You can make it to the Atlantic without being detected if you only travel on the surface at night. It will be slow going and I found a lot of my attempts did not save much time compared to the longer historical routes. The reason for this you will be forced to run submerged for very long periods to remain undetected. Large areas of the Channel are no deeper then 50 meters and even during the first days of the war easily tracked and detected by active sonar. Plus at that depth you do not have a lot of time to avoid the depth charges. Go north of the British Isles and be sure to check the air coverage map.

It can take many hours in game time to evade escorts. The more there are the more likely it will take a rather long time. The longest it has taken me is a little over 24 hours (game time) with six destroyers searching for me in water about 150 meters deep.

This is the time before the Allies have any real effective equipment to counter you, they still pose a threat but it can be easily mitigated with some planning.

Attacking at night on the surface is my preferred method. The visual detection ranges of merchants are greatly reduced at night and a little less for the escorts. With modded versions you can close in further than with the vanilla. Historically during the early war this is how most attacks were conducted. It allows greater situational awareness and maneuverability.

Run with decks awash when nearing the convoy. Below is a u-boat approching a convoy at night ahead slow at 7 meters depth.(Can use diesel engines) You can see the lead escort if you look hard enough. It is about 50 degrees off the conning tower 2,500 meters out.
Same U-boat at ahead slow riding at 8 meters deep(Need to use electric engines) gathering intel on the convoy before attack.
The u-boat can close within 500 meters in the right conditions. In good visability and calm seas around 800 meters is the closest while travelling ahead slow and limiting your profile. This is further in vanilla.

After firing on a single ship about 1,000 meters out.

Passing the lead escort of a convoy in heavy rain and fog. It would have detected me if I was submerged.

Entering the convoy in very poor visability. The green line indicates the planned path of the sub. This will allow the sub to fire the bow torpedoesat the row of ships on the opposite side of the row the sub passes through or any targets towards the stern.

Attacking on the surface allows you to fire your salvo and leave the area very quickly. I generally fire all my torpedoes and then move away from the convoy at full or flank speed depending on conditions. Most times I can be well away from my firing position before the escorts start their search. During the early war before the Allies learned to expect surface attacks from u-boats

An escort speeding to search the area the u-boat was when torpedoes were launched. The u-boat will have plenty of time to come in for another attack while the escort(s) is still searching the wrong area.(Usually, see below picture) The order was given to go above 7 meters and for flank speed seconds before the 1st torpedo impact.

This sub was sunk by the destroyer not circled in the picture. In the picture you can just see it about 3,000 meters out and a little to port of the stern. The captain was so focused on selecting targets and calculating firing solutions he did not see it approaching. He maintained tabs on the destroyer that was circled using search lights but not the one coming at him with no search lights on. After torpedoes were fired and the turn made to escape the next search area the sub was spotted. The destoyer was about 1,000 meters away and the deck guns did some heavy damage before the sub could get below the surface. That destroyer was also able to ram the u-boat before it could get below 10 meters. With the sub taking on water and dive planes damaged it was impossiable to maintain depth without speeds in excess of 3 knots. Depth charges sunk her before she was able to make it back to periscope depth to fight back. So make sure to scan the horizon and do not get too focused on just sinking the merchants. The loss of that sub could have been easily avoided just by scanning for escorts every minute or even every couple of minutes.

I find attacking the escorts a more viable and relatively less risky endeavor very early in the war. They tend not to be as many and are relatively poorly equipped. Keep in mind you will be wasting at least one torpedo that could be used to sink a merchant, except for the smallest they give at least twice as much tonnage.

Only attacked submerged during the day and try to time your attacks on convoys at night. This has the added advantage of allowing you to see the ships on the surface and getting a better understanding of what you are seeing in your UZO or periscope sight. Later in the war surface attacks against convoys will not be an option.

Attack from farther away, you will have access torpedoes that allow for this to be done more successfully. You will have more time to get distance between you and the escorts. Trying to close in to under a 1,000 meters without being detected or being able to escpae undetected will be a lot tougher.

The escorts are better equipped, and better trained. They have Hedgehogs which allows for more accurate targeting since the escort does not lose contact before launching them. So depth is even more important since they will be dropping almost right on target. You need the time to maneuver out of the way.

Attacking in very deep water is almost essential during the late war. I would say if you are dealing with more than one escort in water less than 300 meters you are in for a long and tough time.

Aircraft coverage has increased so to remain undetected in these areas you will need to travel submerged during the day. If you are surfaced during the day during the late war using mods you are likely to be detected at least once if you are on the surface. Snorkels become a requirement to limit detection ranges. I am not sure if the vanilla game increases air coverage as the war progresses.

You will not get away with surface attacks, planning and tracking a convoy becomes more critical. The escorts will be equipped with better detection equipment and there are times you will need to dive deep, run silent to avoid detection then ascend to periscope depth to attack. Take into consideration this will have to be done at slow speed so changing depth and course can take some time and need to be accounted for in your planning.

Never deploy decoys while being actively pinged. The best time is before they detect you and not too early when it will be out of their detection range when it is no longer active. Remember when you deploy it the escorts will search that area. Your max speed without being detected is 2 knots. If you deploy them too late the escorts will be still searching the area you are in.

Accept the fact it becomes much more difficult to avoid detection without diving very deep. Even in vanilla, where it is easier to avoid detection. The risks you could take during the early war will in the best case scenario lead to heavy damage around or after late 1942.

This is by far the best tactic and the only tactic with any chance of success later in the war.

Dive deep, push your sub to the limit, do not try to load torpedoes to get a few extra kills. Convoys are easy to track once you find them. You can attack the convoy again.

Know how deep the water is beneath your keel. Have your navigator get it before attacking.

If you are using a Mod, keep in mind it might be tougher then in vanilla to maintain depth while traveling at 1-2 knots. An experienced and trained crew at the helm helps out a lot.

The deeper you dive the less buoyancy your u-boat has and the more it wants to go deeper. It may require more propulsion or an experienced well tranined crew at the helm to keep your depth.

If your dive planes are damaged it may be impossible to maintain depth without increasing speed. A very important thing to consider if you plan on diving below your crush depth and do not want to be picked up by passive sonar.

If you are using Commander there is an option for simulated thermal layers. As far as I know it is random and there is no way for you to tell in the game. It simulates how a tempature change between water layers can interfer with active sonar. If you get below it the escorts will have a tough time finding you. You still have to run silent since it does not block sound from traveling effectively.

My last bit of advice is patience. It can take awhile to finally evade and lose the escorts searching for you. The more there are the harder and longer it will be to get far enough away from the search area.

Sinking the escorts is also an option that can require a lot of skill and/or luck. Historically u-boat commanders were given orders not to target escorts. The escorts were not as valuable a target as the equipment and supplies the merchants were carrying. Considering the enemy not only lost a ship but what ever that ship was carrying also had to be manufactored again delaying the delivery to Allied forces. The other reasons were they were harder to hit and being warships harder to sink. So was considered a waste of torpedoes. The only time it was considered ok was when every thing else has failed and the u-boat had to surface soon because of damage or out of air.

They tend not to run straight for long periods, can move very fast, and of course unlike merchants they have the ability to track and destroy you.

One option is to lure them to you. This may backfire if the escort does not take a straight course towards you and serpentines. I do not remember this happening to me in the vanilla game, but sure it happens using mods. You can run flank speed, open torpedo tube doors and come in surfaced then dive. If you are successful you now can sink the ships in the convoy at your leisure using your remaining torpedoes and deck gun. Just be cautious later in the war when more merchant ships are armed.

Sometimes you will not have the option. I recommend waiting for a depth charge attack and then ascending to 100 meters if you are not above or near it already. Then when the next escort makes it's attack run wait for the active pings to stop and get to periscope depth ASAP. Use flank speed no since in hiding now, do not forget to make a course change to avoid the depth charges. Have your periscope raised and torpedoes set to magnetic fuses and to run about 4.5 meters deep. You probally have escorts sourounding you and from 300-1500 meters out. You want to shoot point blank and remember your torpedoes do not arm untill 300 meters out.

A escort zig zagging as it approachs after detecting a u-boat. The best chance to hit is with a magnetic detonator aimed not at the ship but the center of it's path or fire a salvo with a very tight spread.

They can damage your periscope with deck and machine gun fire, also you can be rammed at periscope depth. If rammed the periscope, conning tower, hydrophone, or deck gun are the areas that can be damaged. Sometimes it will be your bow torpedo compartment depending if your bow happens to be raised up by wave action.

Keep at flank speed as you will need to be able to maneuver and turn to get descent gyro angles and want the speed to dive fast if need be.

Aim dead center since aiming anywhere else lessen your chance to hit if they make a course or speed change. Depending on the number of escorts, distance and torpedoes available you may want to fire a salvo with a tight spread.

Many times once hit the escort will stop the hunt and imediatley start leaving the area at high speed. They will continue to head away unless they some how make contact with you again. Then they will go back to searching for you. If your shot takes out their propulsion their threat to you is greatly reduced and can be used as cover if needed. Make sure to avoid their stern, just in case the AI will still deploy depth charges in this situation. I have not tested it out, maybe if I have the opportunity I will see what happens.

In the vanilla version I seem to remember it was rather easy to take out the escorts. In the modded version I have been sucessful taking out four hunting me, with a lot of luck. In my experience using manual targeting more than two hunting you and you will be sunk or need to head home for repairs, after burying one or two sailors at sea.