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Improvements are upgrades to equipment that increase their performance or upgrade them to better versions. Improvements are done in Akashi's Improvement Arsenal, requiring Akashi. Improvement Materials Improvement material are notably used for improvements.

  • See the full list of improvable equipment here (this omit the equipment not improvable but obtainable already improved) .
  • See the full list of ship Helpers here.
  • For a comprehensive list of improvements, please refer to Akashi-List or the List of Improvements.

Overview

  1. Improvement levels are displayed beside equipment names.
    • They run from  +1 to   (+10).
  2. Improvement bonuses are hidden. The increase in stats is not reflected on ship girls' stat cards.
    • This means they do not count for Support Expeditions or for reaching certain thresholds like for OASW.
    • Those bonuses work to some extent to reach regular Expeditions thresholds.
    • Some improvements on equipment can add some additional Visible Fit Bonuses.
      • This works on an equipment-to-equipment and ship-to-ship basis with no general rule.
  3. Most conversion quests (e.g. F62), allow to use improved equipment, but any   are lost during conversion.
  4. Certain conversion quests that do not require improved equipment, will carry over any   from the required equipment to the upgraded equipment.

Improvement Bonuses

The bonus stats gained from improvement will vary depending on the type of equipment as well as the stat itself.

  • Most improved stats will come as decimal numbers due to the use as base decimals and how square roots work.
  • It is important to note that decimals must not be discarded in favor of whole numbers, as stats will be multiplied by various formulas anyway, to finally be rounded down/up.
  • For calculated improvment bonuses, please refer to the Categories Charts or Reference Charts.

The improvement effects are unknown for some equipment types/cases.

Square Rooted Bonus

Most bonuses are all a function of the square root of the improvement level. The bonus can be calculated by:

[math]\displaystyle{ \text{Bonus}_\text{stat} = \sum_{\text{All equips}} \text{Mod}_\text{equip} \sqrt{\bigstar} }[/math]
With
  • [math]\displaystyle{ \bigstar }[/math] the improvement level of the equipment.
  • [math]\displaystyle{ \text{Mod}_\text{equip} }[/math] the equipment modifier for that stat, described below:
Equipment Type Day Battle Night Battle ASW AA Fighter Power LoS Accuracy Evasion
Firepower Torpedo Ship Fleet Day Night[1] Torpedo ASW Shelling Torpedo
Main Guns (Very) Large
  Sp
1.5 - 1 - - - - - 1 1.3 - - - -
Medium/Small (Red)
  
1 - 1 - - - - - 1 1.3 - - - -
HA (Green)
 Main
1 - 1 - 2[2]
3[3]
2[2]
3[3]
- - 1 1.3 - - - -
Secondary Guns 90 mm Single HA 
 Sec
1 - 1 - - - 1 1.3 - - - -
(Large) HA (Green)
 Sec  Sp_Sec
Linear 0.2[4]
Linear 0.3[5]
- Linear 0.2[4]
Linear 0.3[5]
- - - 1 1.3 - - - -
Surface (Yellow)
 
- - - - - - 1 1.3 - - - -
15.2 cm Single  & OTO 
 
1 - 1 - - - - - 1 1.3 - - - -
Anti-Aircraft Fire Directors
 
1 - 1 - 2[2]
3[3]
2[2]
3[3]
- - 1 1.3 - - - -
Anti-Air Guns
 
1 1.2 - - 4[2]
6[3]
- - - - - 2 - - -
Torpedoes
 
- 1.2 1 - - - - - - 1.3 2 - - -
Midget Submarines
 Minisub
- - 1 - - - - - - 1.3 - - - -
(Large) Carrier Recons/Large Flying Boats
  Sp 
- - - - - - - 1.2 - - - - - -
LB Recons
 LB
- - - - - - - 1.2?[6] - - - - - -
Seaplanes
  
Recons - - - - - - - 1.2 - - - - - -
Bombers - - - - - - - 1.1 - - - - - -
Rotorcraft/Liaison Aircraft
  
- - - Linear - - - - 1?[7] 1.3?[7] - - - -
Land Based Bombers Attackers/Assault/ASW/Heavy Bombers
    
- 0.7*both   and  [5] - - - - 0.5 - - - - - - -
Hayabusa bomber 
 bomber
- 0.7*only against DD and Installation [6] - - - - - - - - - - -
Radars
 
- - - - - 0[8]
1.5[9]
- 1.25[10]
1.4[11]
1[12]
1.7[13]
1.3[12]
1.6[13]
- - - -
Depth Charges
 
0.75 - - 0.67 - - - - - - - - - -
T95 DC  & T2/K2 DC 
 

 
- - - - - - - - - - - - -
Sonars
 
0.75 - - 0.67 - - - - - - - 1.3 - 1.5
Engine Improvements
 
- - - - - - - - - - - - 1.5
Shells/Searchlights/Lookouts
Landing Equipment/Command Facilities
        
1 - 1 - - - - - 1 1.3 - - - -
Aviation Personnels/Anti-Ground Rockets
Smoke Generators
   
1 - 1 - - - - - 1?[7] 1.3?[7] - - - -
  1. [1]
  2. 2.0 2.1 2.2 2.3 2.4 For base   AA ≤ 7
  3. 3.0 3.1 3.2 3.3 3.4 For base   AA ≥ 8
  4. 4.0 4.1 For base   FP ≤ 3
  5. 5.0 5.1 For base   FP ≥ 5
  6. LoS might be affected like other recons, but it is not measurable, due to how LBAS work.
  7. 7.0 7.1 7.2 7.3 Unconfirmed yet
  8. For Surface Radars
  9. For Air Radars
  10. For Small Radars
  11. For (Very) Large Radars
  12. 12.0 12.1 For base   Acc ≤ 2
  13. 13.0 13.1 For base   Acc ≥ 3

Linear Bonus

Some bonuses have a linear growth. The bonus can be calculated by:

[math]\displaystyle{ \text{Bonus}_\text{stat} = \sum_{\text{All equips}} \text{Mod}_\text{equip} \times \bigstar }[/math]
With
  • [math]\displaystyle{ \bigstar }[/math] the improvement level of the equipment:
  • [math]\displaystyle{ \text{Mod}_\text{equip} }[/math] the equipment modifier for that stat, described below:
Equipment Type Fighter Power Dive Bomb Torpedo ASW Armor
Submarine Torpedoes
 Sub
- - 0.2 - -
Fighters
 
0.2 - - - -
Seaplane Fighters
 
- - - -
LB Fighters
  
- - - -
Fighter-Bombers
 
0.25 - - - -
Mod 64 Zero FB 
 

 
- - 0.2 -
Dive Bombers (ex. FB)
 
- 0.2 - -
Torpedo Bombers
 
- - 0.2 -
Seaplane Bombers
 
- 0.2 - - -
Rotorcraft
 
- - - 0.2[1]
0.3[2]
-
Liaison Aircraft
 [3]
- - - 0.2[4]
0.3[5]
-
Extra Armor
 
Medium - - - - 0.2
Large - - - - 0.3
  1. For base   ASW ≤ 10
  2. For base   ASW ≥ 11
  3. [2][3]
  4. For base   ASW ≤ 7
  5. For base   ASW ≥ 8

Averaged Bonus

The average is counted using all craft on the ship for anti-installation, and all "working" craft in the fleet for expeditions.

All the following bonuses are part of bigger formulas:

Equipment Type Anti-Installation Bonuses[1][2] Expedition Bonus
A1 C
Landing Craft
 
1 + (Average   /50) [1 + (Average   /50)]N[3] 1 + (Average   /100)[4]
Amphibious Vehicles
 
Ka-Mi tank  1 + (Average   /30) 1 + (Average   /30)
Ka-Tsu tanks 
 
1 + (Average   /50) [1 + (Average   /50)]N[3]
Landing Forces
 
Unknown yet -
  1. The average stars are counted per ship on a per-category basis, with each 3 categories being counted separately.
  2. https://bbs.nga.cn/read.php?tid=39595977&rand=587
  3. 3.0 3.1 N = 1 for any Landing Craft/Ka-Tsu, +1 to N for each unique:
  4. Does not work for Type 3 Landing Tanks

Misc Bonuses

Other bonuses observed in the game.

Equipment Type Smoke
Trigger Rate
Smoke Level Support Fleet
Trigger Rate
Smoke Generators
 
Increased[1] Increased[2] -
FCA 
 
- +2 %/ 
for the 2nd roll[3]


It is confirmed that none of the usual stats, probably nothing at all, is given to the following equipment types[4].

Equipment Type Effect
Submarine Equipments
 
"Nothing"
Combat Rations
 
"Nothing"[5]

Myths

The following have been confirmed to be negative.

Visible Fit Bonuses

The following equipment provide additional Visible Fit Bonuses to some ships when improved:

Type Equipment Notes
  38cm Twin Gun Mount Kai 
35.6cm Triple Gun Mount Kai (Dazzle Camouflage) 
16inch Triple Gun Mount Mk.6 
16inch Triple Gun Mount Mk.6 mod.2 
16inch Triple Gun Mount Mk.6 + GFCS  Not improvable
38cm Quadruple Gun Mount Kai Deux 
35.6cm Twin Gun Mount Kai 3 (Dazzle Camouflage) 
35.6cm Twin Gun Mount Kai 4  Not improvable
14inch/45 Twin Gun Mount 
14inch/45 Triple Gun Mount 
35.6cm Twin Gun Mount Kai 3 C  Not improvable
  SKC34 20.3cm Twin Gun Mount 
14cm Twin Gun Mount Kai 
6inch Triple Rapid Fire Gun Mount Mk.16  Not improvable
6inch Triple Rapid Fire Gun Mount Mk.16 mod.2  Not improvable
6inch Mk.XXIII Triple Gun Mount  Not improvable
14cm Twin Gun Mount Kai 2 
Prototype 20.3cm (No.4) Twin Gun Mount 
15.2cm Triple Main Gun Mount 
15.2cm Triple Main Gun Mount Kai  Not improvable
  12.7cm Single Gun Mount 
12.7cm Twin Gun Mount Model D Kai 2 
12.7cm Twin Gun Mount Model A Kai 2 
12.7cm Twin Gun Mount Model D Kai 3  Not improvable
120mm/50 Twin Gun Mount Kai A.mod.1937 
12.7cm Twin Gun Mount Model C Kai 3 
12.7cm Twin Gun Mount Model C Kai 3 H 
13.8cm Twin Gun Mount 
13.8cm Twin Gun Mount Kai  Not improvable
 Small 10cm Twin High-angle Gun Mount + Anti-Aircraft Fire Director 
12.7cm Single High-angle Gun Mount (Late Model) 
Locally Modified 12.7cm Twin High-angle Gun Mount  Not improvable
Locally Modified 10cm Twin High-angle Gun Mount  Not improvable
12cm Single High-angle Gun Mount Model E Kai 
  15.2cm Triple Gun Mount 
 Sec 12.7cm High-angle Gun + Anti-Aircraft Fire Director 
8cm High-angle Gun Kai + Additional Machine Guns 
10cm Twin High-angle Gun Mount Kai + Additional Machine Guns 
65mm/64 Single Rapid Fire Gun Mount Kai  Not improvable
12cm Single High-angle Gun Mount + 25mm Machine Guns Additions 
  25mm Twin Autocannon Mount 
25mm Triple Autocannon Mount 
25mm Single Autocannon Mount 
25mm Triple Autocannon Mount (Concentrated Deployment) 
2cm Flakvierling 38 
3.7cm FlaK M42  Not improvable
  53cm Twin Torpedo Mount  Only as synergy
61cm Triple (Oxygen) Torpedo Mount Late Model 
61cm Quadruple (Oxygen) Torpedo Mount Late Model 
 Sub Late Model 53cm Bow Torpedo Mount (8 tubes) 
Skilled Sonar Personnel + Late Model Bow Torpedo Mount (4 tubes)  Not improvable
  Seafire Mk.III Kai  Not improvable
Shiden Kai 4 
Type 0 Fighter Model 64 (Air Superiority Fighter Specification) 
  SBD-5 
SB2C-3 
SB2C-5 
Type 0 Fighter Model 64 (Two-seat w/ KMX) 
Type 0 Fighter Model 64 (Skilled Fighter-bomber) 
SBD (Yellow Wings)  Not improvable
SBD VB-2 (Bomber Squadron)  Not improvable
  Barracuda Mk.II 
Barracuda Mk.III 
TBD (Yellow Wings)  Not improvable
  Saiun  Not improvable
Type 2 Reconnaissance Aircraft 
Saiun (Eastern Caroline Air Group)  Not improvable
Saiun (4th Recon Squad)  Not improvable
Fulmar (Reconnaissance Fighter/Skilled)  Not improbable
SBD VS-2 (Reconnaissance Squadron)  Not improbable
 Sp Prototype Keiun (Carrier-based Reconnaissance Model) 
 Recon Ar196 Kai 
Shiun 
OS2U 
SOC Seagull 
SOC Seagull Late Model (Skilled)  Not improvable
SO3C Seamew Kai  Not improvable
Shiun (Skilled)  Not improvable
Type 0 Small Reconnaissance Seaplane  Not improvable
Type 0 Small Reconnaissance Seaplane (Skilled)  Not improvable
  Loire 130M 
Loire 130M Kai (Skilled)  Not improvable
  Kyoufuu Kai 2 
  Type 3 Command Liaison Aircraft Kai 
Type 1 Fighter Hayabusa Model II Kai (20th Squadron)  Not improvable
Type 1 Fighter Hayabusa Model III Kai (Skilled/20th Squadron)  Not improvable
  Type 2 Depth Charge 
Type 2 Depth Charge Kai 2 
 Small Type 3 Active Sonar Kai 
 Large Type 0 Passive Sonar 
 Small Type 13 Air Radar Kai (Late Model) 
Passive Radiolocator (E27) + Type 22 Surface Radar Kai 4 (Calibrated Late Model) 
 Large FuMO25 Radar 
Type 21 Air Radar Kai 2 
Type 42 Air Radar Kai 2  Not improvable
Type 281 Radar  Not improvable
Type 274 Fire Control Radar  Not improvable
  Late Model Radar & Passive Radiolocator + Snorkel Equipment  Not improvable
  Type 3 Shell Kai 
Type 3 Shell Kai 2 
  Torpedo Squadron Skilled Lookouts  Not improvable
  New Model High Temperature High Pressure Boiler 
 Large Pugliese Underwater Protection Bulkhead 
New Kanhon Design Anti-torpedo Bulge (Large) 
  Skilled Deck Personnel + Aviation Maintenance Hands 
  Fleet Communication Antenna 
  Special Type 4 Amphibious Tank  Not improvable
Special Type 4 Amphibious Tank Kai  Not improvable

Equipability

The following equipment have enhanced equipability when improved:

Resource Node Bonus

Uniquely on the Resource Nodes of 1-6 and 3-5, improvements   slightly increase resource gains.

Special Resource Nodes Gain Modifiers
Type 2
Equipment / Ship Bonus Gains (per DLC / Ship)[1]
Type Name 1-6 3-5
N G
 
G
 [2]
M
 
M
 [2]
J
 
J
 [2]
 
 
A 1 Toku Daihatsu Landing Craft  0.0 6.00 0.3800? 12.00 0.?? 24.00 0.??
2 Ka-Tsu Tank Kai  5.50 0.?? 11.00 0.?? 22.00 0.2??
3 Daihatsu Landing Craft  5.00 0.0350? 10.00 0.?? 20.00 0.??
4 Ka-Tsu Tank  4.50 0.?? 9.00 0.?? 18.00 0.2??
5 Armed Daihatsu  2,50 0.0720? 5.00 0.?? 10.00 0.??
6 DLC + T89 Tank 
DLC + Panzer II 
1.50 0.0100? 3.00 0.?? 6.00 0.??
7 Soukoutei 
Toku DLC + Ho-Ni Tank 
1.10 0.0200? 2.20 0.?? 4.40 0.??
8 Ka-Mi Tank  0.75 0.0041? 1.50 0.?? 3.00 0.??
  B Drums  0.0 N/A 0.0 N/A 10.0 N/A
  C Toku DLC + 11th Reg 
M4A1 DD 
Toku DLC + Panzer III 
Toku DLC + Chi-Ha 
Toku DLC + Chi-Ha Kai 
Toku DLC + Panzer III J 
0.0
Ship Kinu Kai Ni [3] 5.0 N/A 10.0 N/A 20.00 N/A
Other Ships 0.0 0.0 0.0
Resource Cap N/A 40 80 150
Random Resource Increments N/A 0 0 0
Star Bonus[2]
[math]\displaystyle{ \text{Bonus}_\text{Star} = \sum_\text{All Types} \text{N}_\text{Type}^2 \times \sqrt{\text{N}_\text{Star Type} } \times \text{Star Bonus}_\text{Type} }[/math]
With
  • [math]\displaystyle{ \text{Bonus}_\text{Star} }[/math] the total bonus resource gain bonus for the fleet,
  • [math]\displaystyle{ \text{N}_\text{Type} }[/math] the number of craft of a given type (A1 to A6),
  • [math]\displaystyle{ \text{N}_\text{Star Type} }[/math] the total number of stars on a given type,
  • [math]\displaystyle{ \text{Star Bonus}_\text{Type} }[/math] the bonus given by stars of each type.

Notes:

  1. If the total value has a decimal, only the rounded-down value is applied.
  2. 2.0 2.1 2.2 2.3 Exact values an behaviors still under investigation
  3. Those bonuses only appear if any type from A1 to A8 is equipped in the fleet.

Sources: [7] [8] [9] [10] [11]

Expeditions Bonus

For expedition stats requirements, improvements   are globally simplified, overwriting the above-mentioned improvements.

  • See here for more details

See Also