Post by keyboy on Apr 10, 2017 18:02:23 GMT
3.1.7.6. Air Raids on Ports. Starting in Jan 1944, before checking for Patrol Assignment, you must check for air raid damage if assigned to a German, Norwegian, or Med port:
Roll 2d6:
2: Boat destroyed in an air raid. Spend one month to transfer to a new boat, then repeat procedure.
3: Boat heavily damaged in air raid. Add 2 months to current refit, then sail.
4: Boat damaged in an air raid. Add 1 month to current refit, then sail.
5-12: No effect. Proceed to Patrol assignment.
Die roll modifiers: +1 for Norway, -1 for the Med. France and Penang do not check. (Historical note: Despite all the hype about the "Tall Boy" bombs, the bunkers in France did a superb job of protection from bombing.)
3.1.8 Deck gun removal.
The Germans decided that deck guns were essentially a waste by June 1943, and ordered them removed. However, this happened in stages, with some U-boats keeping their guns for quite some time. Before each patrol, roll 1d6:
1-4 Deck gun removed
5-6 Deck gun retained
This step does not apply to patrols heading to the Indian Ocean. (They retained their deck guns.)
The Kommandant may influence die roll in EITHER direction by "1" if a Korvettenkapitän or higher rank.
Continue to roll before each patrol starts until the deck gun is removed. You then may skip this step for the rest of the game. Exception: If later chosen to go to the Indian Ocean, the deck gun is assumed to be reinstalled. You then check for removal again on later patrols.
Extra Flak: If removed, the deck gun box on your U-Boat chart is converted to "Extra Flak." Place the extra flak counter there. It may be damaged by a "Flak guns hit" result (which takes out all flak guns.) While undamaged, it provides an additional "-1" modifier to the flak firing die roll. The "Extra Flak" counter represents any of a myriad of flak configurations that were used in the latter half of the war.
3.2.4 ANTI-INVASION patrol. In the June-July 1944 timeframe, many Type VII U-Boats were essentially sent to their deaths when they were assigned to help stop the Allied invasion of France at Normandy. Massive amounts of aircraft flew non-stop patrols to the north and south of the invasion zone. Still, some U-Boat captains actually penetrated this screen and sank shipping. Most, however, were sunk by aircraft, and a few by the extra patrol craft.
IF assigned "Invasion" as the patrol zone, the player conducts transit normally, then uses the Atlantic chart to process encounters while on station. However, any "---" result, which would normally be "no encounter" is instead processed as an "aircraft" encounter.
A player is not allowed to abort before rolling for encounters (similar to being assigned to the Med) unless he suffers at least 1 nonrepairable damage or 1 seriously wounded crewman.
4.1.2.1 The Focke-Achgelis Fa-330 Kite. Some boats were equipped with the Fa-330, a rotary kite that was towed behind the boat to extend view range. You may choose to deploy the kite in the Indian Ocean, Brazilian Coast, Australia, or West African coast. Flip the Fa-330 counter to the "Deployed" side. If you do so, and roll a "5" (no encounter) on Chart A3, you may roll again. If another "5" occurs, there is no encounter and you move to the next travel box. If you have your kite deployed and an aircraft encounter occurs, you must cut the kite loose when you dive, and you lose an officer ( for the rest of the patrol. Roll 1d6 if this occurs: 1-2= Doctor lost 3-4= 2WO lost 5-6 Unnamed Petty officer lost.
4.1.10 SWITCHING FROM DAY TO NIGHT. If you want to prosecute a contact in the day and you rolled for "night" or vice versa, you may do so by taking a small risk of losing contact. Roll 1d6: 1-4 is successful, 5-6 means the target contact is lost (and so is your encounter for that travel box.) Balkon-Gerät equipped boats are successful on a 1-5 and lose the contact on a 6.
You CANNOT switch from day/night or night/day versus a Capital ship (they are simply too fast).
4.2.3.1 FaT torpedo attacks. A new type of guidance system for torpedoes became available in December 1942. Known as the "Federapparat Torpedo" or "FaT" it was a guidance system that kicked in after a set distance and made the torpedo travel in a "ladder" search pattern, somewhat resembling a flattened "S" shape.
Against a convoy, if the U-boat missed the original target, it had a better chance to still hit a random ship. When attached to a G7a, it was called the "FaT I" and when attached to the G7e, it was known as the "FaT II".
If a FaT-equipped torpedo misses a convoy target (only) the player rolls again. On a 2d6 roll of "2-3" (no modifiers) the FaT pattern has worked and the torpedo hits a new, random target.
4.2.3.2 Homing torpedo attacks. The 3 types of homing torpedo (G7e "Falke" and the G7es "Zaunkonig" / "Zaunkonig II" have minimum "to hit" numbers of 5,6, and 7 respectively. They may have a higher number than that (for example, if fired at close range) but regardless of modifiers due to range or other factors, the hit number will always be at least that minimum.
4.2.5 Escorted ships. In "The Hunted" each cycle of depth-charging may involve a "Special Attack" instead. Before the escort attacks, roll 1d6. On a roll of "1-5" the normal depth charge attack occurs. On a roll of "6" a "Special Attack" occurs instead. If a special occurs, roll again to see if it a Hedgehog attack (dangerous), or a Squid attack (VERY dangerous.) After determining the type of special attack, roll again to see if the U-boat is missed, sunk outright, or takes serious damage per chart E3.
For each "hit" on chart E3, roll once on chart B5 to determine the damage from the depth charges. After the damage is applied to the U-boat, and additional flooding is checked for on chart B6, the cycle continues. AGAIN roll for detection, now applying the "+1" for previous detection AND any new modifiers such as dive plane or fuel tank damage, and if detected again, roll again on Chart E3. Rounds of combat continue with detecting/attacking until the U-boat finally escapes detection on chart E2, or is sunk. Players will notice it is more difficult to evade detection in subsequent combat rounds, especially if a lot of damage occurs.
4.2.5.2 BOLD decoy. German U-boats may attempt to decoy the Allied ASW forces by releasing a BOLD canister. Only one BOLD canister may be used per encounter, however, it may be combined with exceeding test depth. The decision to use BOLD occurs before the escort detection roll is made. It gives a temporary -1 to the detection roll. If using the optional rule "Variable Escort Quality" BOLD does NOT work against Veteran or Elite Escorts. The decision to use it occurs before Escort Quality is rolled.
4.2.5.3 "Alberich" Anti-sonar coating. A handful of Type VIIC and VIIC/41 boats were equipped with "Alberich," a synthetic rubber coating, glued onto the hull, that reduced sonar effectiveness. Named after a mythical dwarf that could become invisible, it had numerous initial problems, including lack of adhesion after time. By 1944 most of the issues had been solved, but the synthetic rubber was extremely scarce and Alberich, still in testing, was only placed on a handful of new boats.
-Starting in 6/44, any upgrade to a new Type VIIC or Type VIIC/41 has a small chance for an Alberich coating. It is present on a 2d6 roll of "12." -Alberich reduces the detection roll by -1 at all times, in addition to any other modifiers.
DEFENSIVE EQUIPMENT: On chart A1, two items may help reduce your chances of being spotted in the first place - the SCHNORCHEL, or the NAXOS radar detector. However, because of their employment, you can ONLY benefit from one or the other at a time. (The NAXOS was placed up on the bridge during surface running. The Schnorchel was employed while the boat was just below the surface, in order to recharge batteries with a greatly reduced surface signature. (The Schnorchel could still be seen or detected by radar, but it was a much, much smaller signature.)
Exception: Type XXI U-boats may schnorchel and use their NAXOS at the same time, for a combined +3 for crash diving purposes.
Obviously you cannot be simultaneously surfaced and submerged, so only one of the two systems can be used for any one die roll on chart A1. Before entering a travel box, you must decide to be either surface running, or schnorcheling. Flip your U-boat marker to the appropriate side. If an aircraft encounter occurs, you use the NAXOS -1 drm if on the surface, and the Schnorchel -2 drm if schnorcheling. If schnorcheling and hit by aircraft, you do not suffer the mandatory crew injury from strafing (as there is nobody on deck) but you also do not get to use your flak guns.
Another side effect of schnorcheling is other than aircraft, convoys, and random events, all other encounters are treated as "no encounter." (you have no lookouts and very limited vision through the periscope.)
Schnorcheling cannot be chosen in a "Mission" travel box if you are on a mission.
Schnorcheling cannot be chosen as a travel option if the U-boat's hull has been holed by a rocket or 57mm "Tsetse" gun attack.
4.2.10.3
Combat against Escorts. Unlike the earlier half of the Atlantic war, combat against escorts (or just warships in general) happened with more regularity in the second half, due to a shift in command directives and the advent of the G7es homing torpedo. To represent this, players ARE allowed (but not required) to attack an escort that is with the target ship(s). To attack an escort, add a generic Escort target (2000 tons). This ship can now be added to the other available ship targets and is attacked normally per the attack rules. (Although there is more than one escort, just like there are more than 4 cargo ships in a convoy, it is assumed there will only be one in your "window of opportunity" to attack when you start.) Escorts are significantly faster than cargo ships, and smaller, and get an automatic +2 drm to torpedo hit rolls against them.
4.2.10.4 If the escort is sunk/damaged, detection rolls for the rest of the combat are made at -1 (and of course you receive credit for that escort's tonnage if sunk). If the escort survives your salvo unharmed, detection rolls are made at +1 for the rest of the combat. If you are using optional escort quality rules, you do not reroll quality. If only damaged, the escort may still be attacked at a later time.
4.3.3.1 Aircraft Special Attacks. Similar to the Hedgehog and Squid attacks, aircraft may also use "special" weapons (essentially, anything other than a standard depth charge/strafing attack.) If a special attack occurs due to a die roll of "6" you then roll an additional 1d6. There are 3 types of special attacks:
Roll: Attack:
1-4 FIDO homing torpedo.
5 "Tsetse" equipped aircraft (57mm cannon)
6 Rocket equipped aircraft (using 8 x 3" rockets)
4.3.3.2 Application of special attacks.
1. A FIDO attack means the aircraft has dropped a homing torpedo. The good news is, this type of aircraft attack does not generate an automatic crew casualty. The bad news is, if the FIDO hits the U-Boat and detonates, it is automatically sunk or takes 7 hits per the chart.
2. A "Tsetse" attack consists of a strafing run to include 57mm cannon shells that are capable of penetrating a U-boat's hull. This attack is conducted normally per the aircraft attack rules, however, IF there is one or more "hull hits" as damage, the Hull Damage marker is flipped to the "Hull Holed" side and the U-boat may no longer submerge this patrol. Obviously the U-Boat may also be sunk outright, but if it survives with a hull hit, it presents serious issues for survival. Additionally, IF the aircraft is not damaged or shot down, and a hull hit occurs, it will have time to reload the 57mm cannon out of range, and will re-attack since the U-boat cannot submerge. It may reload twice in this manner, for a total of 3 attacks assuming the U-boat fails to damage or shoot it down.
If a "2 aircraft attacks" result is rolled for and then a "Tsetse" special attack rolled for, the "Tsetse" aircraft gets to attack twice, even if damaged. (Either the pilot is extremely determined, or the aircraft damage was not perceived as very severe.) If, after the second attack of a "2 aircraft attacks" result, the aircraft is still not damaged, it may reload and attack a 3rd time, which is the maximum for a "Tsetse" equipped aircraft.
3. A rocket-equipped aircraft is also capable of penetrating a U-Boat's hull. It will attack by strafing and firing 8 rockets. This attack is also conducted normally per the aircraft attacks rules, however, IF there is one or more "hull hits" as damage, the Hull Damage marker is flipped to the "Hull Holed" side and the U-Boat may no longer submerge this patrol.
4. Additional Rounds of Combat if the hull is holed. If the U-boat has been holed, it may not submerge, and if additional aircraft arrive, it must fight it out on the surface with flak (if able) and basically try to survive the damage. If an escort arrives, the U-boat must scuttle and the game ends. If it survives an aircraft attack and has a holed hull, the U-boat must abort the patrol.
SPECIAL RULE: "Hunting to Exhaustion." If any combination of aircraft/escorts occurs 4 times with the additional round of combat cycle, you have been considered to have been "Hunted to Exhaustion." With almost no air and no battery power remaining, you must surface and scuttle.
4.5.9.3 SCHNORCHEL upgrade. New boats from construction arrive with a Schnorchel starting in Feb 1944, but older boats had to get them upgraded as they became available. Each time you come in to refit, roll 1d6. A roll of "1" allows the schnorchel to be installed. This roll is modified by -1 for each rank the Kommandant has above OberLeutnant zur See, -1 if he holds the Knight's Cross or above, and -1 for each previous attempt.
5.0.4.1 "Balkon-Gerät" improved hydrophones. Literally "Balcony device," this was an improved model of hydrophones. It was standard on Type XXI U-boats and was being installed and retrofitted into Type IXs. Starting in January 1944, any Type IX in refit can receive Balkon-Gerät on a 1d6 roll of 1-2. Any U-boat upgrade to any model of Type IX similarly may start with Balkon-Gerät on a 1d6 roll of 1-3. The Balkon-Gerät gives a better chance of switching day to night, and following convoys.
Roll 2d6:
2: Boat destroyed in an air raid. Spend one month to transfer to a new boat, then repeat procedure.
3: Boat heavily damaged in air raid. Add 2 months to current refit, then sail.
4: Boat damaged in an air raid. Add 1 month to current refit, then sail.
5-12: No effect. Proceed to Patrol assignment.
Die roll modifiers: +1 for Norway, -1 for the Med. France and Penang do not check. (Historical note: Despite all the hype about the "Tall Boy" bombs, the bunkers in France did a superb job of protection from bombing.)
3.1.8 Deck gun removal.
The Germans decided that deck guns were essentially a waste by June 1943, and ordered them removed. However, this happened in stages, with some U-boats keeping their guns for quite some time. Before each patrol, roll 1d6:
1-4 Deck gun removed
5-6 Deck gun retained
This step does not apply to patrols heading to the Indian Ocean. (They retained their deck guns.)
The Kommandant may influence die roll in EITHER direction by "1" if a Korvettenkapitän or higher rank.
Continue to roll before each patrol starts until the deck gun is removed. You then may skip this step for the rest of the game. Exception: If later chosen to go to the Indian Ocean, the deck gun is assumed to be reinstalled. You then check for removal again on later patrols.
Extra Flak: If removed, the deck gun box on your U-Boat chart is converted to "Extra Flak." Place the extra flak counter there. It may be damaged by a "Flak guns hit" result (which takes out all flak guns.) While undamaged, it provides an additional "-1" modifier to the flak firing die roll. The "Extra Flak" counter represents any of a myriad of flak configurations that were used in the latter half of the war.
3.2.4 ANTI-INVASION patrol. In the June-July 1944 timeframe, many Type VII U-Boats were essentially sent to their deaths when they were assigned to help stop the Allied invasion of France at Normandy. Massive amounts of aircraft flew non-stop patrols to the north and south of the invasion zone. Still, some U-Boat captains actually penetrated this screen and sank shipping. Most, however, were sunk by aircraft, and a few by the extra patrol craft.
IF assigned "Invasion" as the patrol zone, the player conducts transit normally, then uses the Atlantic chart to process encounters while on station. However, any "---" result, which would normally be "no encounter" is instead processed as an "aircraft" encounter.
A player is not allowed to abort before rolling for encounters (similar to being assigned to the Med) unless he suffers at least 1 nonrepairable damage or 1 seriously wounded crewman.
4.1.2.1 The Focke-Achgelis Fa-330 Kite. Some boats were equipped with the Fa-330, a rotary kite that was towed behind the boat to extend view range. You may choose to deploy the kite in the Indian Ocean, Brazilian Coast, Australia, or West African coast. Flip the Fa-330 counter to the "Deployed" side. If you do so, and roll a "5" (no encounter) on Chart A3, you may roll again. If another "5" occurs, there is no encounter and you move to the next travel box. If you have your kite deployed and an aircraft encounter occurs, you must cut the kite loose when you dive, and you lose an officer ( for the rest of the patrol. Roll 1d6 if this occurs: 1-2= Doctor lost 3-4= 2WO lost 5-6 Unnamed Petty officer lost.
4.1.10 SWITCHING FROM DAY TO NIGHT. If you want to prosecute a contact in the day and you rolled for "night" or vice versa, you may do so by taking a small risk of losing contact. Roll 1d6: 1-4 is successful, 5-6 means the target contact is lost (and so is your encounter for that travel box.) Balkon-Gerät equipped boats are successful on a 1-5 and lose the contact on a 6.
You CANNOT switch from day/night or night/day versus a Capital ship (they are simply too fast).
4.2.3.1 FaT torpedo attacks. A new type of guidance system for torpedoes became available in December 1942. Known as the "Federapparat Torpedo" or "FaT" it was a guidance system that kicked in after a set distance and made the torpedo travel in a "ladder" search pattern, somewhat resembling a flattened "S" shape.
Against a convoy, if the U-boat missed the original target, it had a better chance to still hit a random ship. When attached to a G7a, it was called the "FaT I" and when attached to the G7e, it was known as the "FaT II".
If a FaT-equipped torpedo misses a convoy target (only) the player rolls again. On a 2d6 roll of "2-3" (no modifiers) the FaT pattern has worked and the torpedo hits a new, random target.
4.2.3.2 Homing torpedo attacks. The 3 types of homing torpedo (G7e "Falke" and the G7es "Zaunkonig" / "Zaunkonig II" have minimum "to hit" numbers of 5,6, and 7 respectively. They may have a higher number than that (for example, if fired at close range) but regardless of modifiers due to range or other factors, the hit number will always be at least that minimum.
4.2.5 Escorted ships. In "The Hunted" each cycle of depth-charging may involve a "Special Attack" instead. Before the escort attacks, roll 1d6. On a roll of "1-5" the normal depth charge attack occurs. On a roll of "6" a "Special Attack" occurs instead. If a special occurs, roll again to see if it a Hedgehog attack (dangerous), or a Squid attack (VERY dangerous.) After determining the type of special attack, roll again to see if the U-boat is missed, sunk outright, or takes serious damage per chart E3.
For each "hit" on chart E3, roll once on chart B5 to determine the damage from the depth charges. After the damage is applied to the U-boat, and additional flooding is checked for on chart B6, the cycle continues. AGAIN roll for detection, now applying the "+1" for previous detection AND any new modifiers such as dive plane or fuel tank damage, and if detected again, roll again on Chart E3. Rounds of combat continue with detecting/attacking until the U-boat finally escapes detection on chart E2, or is sunk. Players will notice it is more difficult to evade detection in subsequent combat rounds, especially if a lot of damage occurs.
4.2.5.2 BOLD decoy. German U-boats may attempt to decoy the Allied ASW forces by releasing a BOLD canister. Only one BOLD canister may be used per encounter, however, it may be combined with exceeding test depth. The decision to use BOLD occurs before the escort detection roll is made. It gives a temporary -1 to the detection roll. If using the optional rule "Variable Escort Quality" BOLD does NOT work against Veteran or Elite Escorts. The decision to use it occurs before Escort Quality is rolled.
4.2.5.3 "Alberich" Anti-sonar coating. A handful of Type VIIC and VIIC/41 boats were equipped with "Alberich," a synthetic rubber coating, glued onto the hull, that reduced sonar effectiveness. Named after a mythical dwarf that could become invisible, it had numerous initial problems, including lack of adhesion after time. By 1944 most of the issues had been solved, but the synthetic rubber was extremely scarce and Alberich, still in testing, was only placed on a handful of new boats.
-Starting in 6/44, any upgrade to a new Type VIIC or Type VIIC/41 has a small chance for an Alberich coating. It is present on a 2d6 roll of "12." -Alberich reduces the detection roll by -1 at all times, in addition to any other modifiers.
DEFENSIVE EQUIPMENT: On chart A1, two items may help reduce your chances of being spotted in the first place - the SCHNORCHEL, or the NAXOS radar detector. However, because of their employment, you can ONLY benefit from one or the other at a time. (The NAXOS was placed up on the bridge during surface running. The Schnorchel was employed while the boat was just below the surface, in order to recharge batteries with a greatly reduced surface signature. (The Schnorchel could still be seen or detected by radar, but it was a much, much smaller signature.)
Exception: Type XXI U-boats may schnorchel and use their NAXOS at the same time, for a combined +3 for crash diving purposes.
Obviously you cannot be simultaneously surfaced and submerged, so only one of the two systems can be used for any one die roll on chart A1. Before entering a travel box, you must decide to be either surface running, or schnorcheling. Flip your U-boat marker to the appropriate side. If an aircraft encounter occurs, you use the NAXOS -1 drm if on the surface, and the Schnorchel -2 drm if schnorcheling. If schnorcheling and hit by aircraft, you do not suffer the mandatory crew injury from strafing (as there is nobody on deck) but you also do not get to use your flak guns.
Another side effect of schnorcheling is other than aircraft, convoys, and random events, all other encounters are treated as "no encounter." (you have no lookouts and very limited vision through the periscope.)
Schnorcheling cannot be chosen in a "Mission" travel box if you are on a mission.
Schnorcheling cannot be chosen as a travel option if the U-boat's hull has been holed by a rocket or 57mm "Tsetse" gun attack.
4.2.10.3
Combat against Escorts. Unlike the earlier half of the Atlantic war, combat against escorts (or just warships in general) happened with more regularity in the second half, due to a shift in command directives and the advent of the G7es homing torpedo. To represent this, players ARE allowed (but not required) to attack an escort that is with the target ship(s). To attack an escort, add a generic Escort target (2000 tons). This ship can now be added to the other available ship targets and is attacked normally per the attack rules. (Although there is more than one escort, just like there are more than 4 cargo ships in a convoy, it is assumed there will only be one in your "window of opportunity" to attack when you start.) Escorts are significantly faster than cargo ships, and smaller, and get an automatic +2 drm to torpedo hit rolls against them.
4.2.10.4 If the escort is sunk/damaged, detection rolls for the rest of the combat are made at -1 (and of course you receive credit for that escort's tonnage if sunk). If the escort survives your salvo unharmed, detection rolls are made at +1 for the rest of the combat. If you are using optional escort quality rules, you do not reroll quality. If only damaged, the escort may still be attacked at a later time.
4.3.3.1 Aircraft Special Attacks. Similar to the Hedgehog and Squid attacks, aircraft may also use "special" weapons (essentially, anything other than a standard depth charge/strafing attack.) If a special attack occurs due to a die roll of "6" you then roll an additional 1d6. There are 3 types of special attacks:
Roll: Attack:
1-4 FIDO homing torpedo.
5 "Tsetse" equipped aircraft (57mm cannon)
6 Rocket equipped aircraft (using 8 x 3" rockets)
4.3.3.2 Application of special attacks.
1. A FIDO attack means the aircraft has dropped a homing torpedo. The good news is, this type of aircraft attack does not generate an automatic crew casualty. The bad news is, if the FIDO hits the U-Boat and detonates, it is automatically sunk or takes 7 hits per the chart.
2. A "Tsetse" attack consists of a strafing run to include 57mm cannon shells that are capable of penetrating a U-boat's hull. This attack is conducted normally per the aircraft attack rules, however, IF there is one or more "hull hits" as damage, the Hull Damage marker is flipped to the "Hull Holed" side and the U-boat may no longer submerge this patrol. Obviously the U-Boat may also be sunk outright, but if it survives with a hull hit, it presents serious issues for survival. Additionally, IF the aircraft is not damaged or shot down, and a hull hit occurs, it will have time to reload the 57mm cannon out of range, and will re-attack since the U-boat cannot submerge. It may reload twice in this manner, for a total of 3 attacks assuming the U-boat fails to damage or shoot it down.
If a "2 aircraft attacks" result is rolled for and then a "Tsetse" special attack rolled for, the "Tsetse" aircraft gets to attack twice, even if damaged. (Either the pilot is extremely determined, or the aircraft damage was not perceived as very severe.) If, after the second attack of a "2 aircraft attacks" result, the aircraft is still not damaged, it may reload and attack a 3rd time, which is the maximum for a "Tsetse" equipped aircraft.
3. A rocket-equipped aircraft is also capable of penetrating a U-Boat's hull. It will attack by strafing and firing 8 rockets. This attack is also conducted normally per the aircraft attacks rules, however, IF there is one or more "hull hits" as damage, the Hull Damage marker is flipped to the "Hull Holed" side and the U-Boat may no longer submerge this patrol.
4. Additional Rounds of Combat if the hull is holed. If the U-boat has been holed, it may not submerge, and if additional aircraft arrive, it must fight it out on the surface with flak (if able) and basically try to survive the damage. If an escort arrives, the U-boat must scuttle and the game ends. If it survives an aircraft attack and has a holed hull, the U-boat must abort the patrol.
SPECIAL RULE: "Hunting to Exhaustion." If any combination of aircraft/escorts occurs 4 times with the additional round of combat cycle, you have been considered to have been "Hunted to Exhaustion." With almost no air and no battery power remaining, you must surface and scuttle.
4.5.9.3 SCHNORCHEL upgrade. New boats from construction arrive with a Schnorchel starting in Feb 1944, but older boats had to get them upgraded as they became available. Each time you come in to refit, roll 1d6. A roll of "1" allows the schnorchel to be installed. This roll is modified by -1 for each rank the Kommandant has above OberLeutnant zur See, -1 if he holds the Knight's Cross or above, and -1 for each previous attempt.
5.0.4.1 "Balkon-Gerät" improved hydrophones. Literally "Balcony device," this was an improved model of hydrophones. It was standard on Type XXI U-boats and was being installed and retrofitted into Type IXs. Starting in January 1944, any Type IX in refit can receive Balkon-Gerät on a 1d6 roll of 1-2. Any U-boat upgrade to any model of Type IX similarly may start with Balkon-Gerät on a 1d6 roll of 1-3. The Balkon-Gerät gives a better chance of switching day to night, and following convoys.