Help:Akashi Upgrades

Introduction

This article aims to provide a rough guide to help you decide on what to spend screws on. Because most improvement bonuses are "square-rooted", the first upgrade provides the largest relative gain per screw, therefore it is critical to get relevant important equipment to  +1 before working on others. Please refer to:

The Breakpoint Myth

Breakpoints refer to points where upgrade bonuses reach whole numbers. These points are stressed because of the way the game rounds down the results of most formulas. The misconception is that a 1.99 bonus is just as good as a 1.00 bonus because of rounding. While there is a slight grain of truth to the myth, things get a little complex in practice. Due to how many multipliers and other bonuses are involved, trying to hit equipment upgrade breakpoints doesn't affect very much in the grand scheme of things.

The most important thing to do is to upgrade your equipment to certain critical points:

  •  +1 : Provides the biggest power increase (square-rooted only).
  •  +6 : The point when failures start to kick in and costs take a jump.
  •   : The final step to maximize upgrade bonuses.

Screw Guaranteeing/Saving

In most cases, it is statistically cheaper to either toggle or not the "guaranteed improvement".

Reminder :

Modification Level 1★ 2★ 3★ 4★ 5★ 6★ 7★ 8★ 9★ Max★ Upgrade
Akashi 100% 100% 100% 100% 95% 90% 80% 77% 72% 60% 50%
Akashi Kai 100% 100% 100% 100% 100% 95% 90% 82% 77% 67% 62%

Average screw cost when not guaranteed, assuming Akashi is Kai and not counting any equipment cost:

As expected, when the guaranteed cost is too high, not guaranteeing the upgrade is on average cheaper screw-wise, but this is not counting any potential equipment that may be lost and so may imply a higher screw cost.

Guaranteeing worthiness per base upgrade screw cost can then be defined as followed:

When upgrading any equipment, Devmats and Screw are consumed, and eventually one or several equipment and consumables.

  • Since obtaining Devmats is not an issue, their cost is simply ignored.
  • Since failing an upgrade does not consume any consumables, they are ignored.
  • For equipment consumed :
    • If they are craftable or relatively easy to obtain, their cost is negligible in front of any screw cost.
    • If the equipment consumed is a very rare one, then guaranteeing the upgrade should be evident.
    • If the equipment consumed is itself made via Akashi's upgrades, then its total screw cost must be added to the base screw costs used in later examples.

guaranteed cost 1st time guaranteeing is worth it (in  )
0 6th  
1+ Never

guaranteed cost 1st time guaranteeing is worth it (in  )
1 6th  
2+ Never

guaranteed cost 1st time guaranteeing is worth it (in  )
2 6th  
3  
4+ Never

guaranteed cost 1st time guaranteeing is worth it (in  )
3 6th  
4 8th  
5+ Never

guaranteed cost 1st time guaranteeing is worth it (in  )
4 6th  
5 8th  
6  
7+ Never

guaranteed cost 1st time guaranteeing is worth it (in  )
5 6th  
6 7th  
7 9th  
8  
9+ Never

guaranteed cost 1st time guaranteeing is worth it (in  )
6 6th  
7 7th  
8 9th  
9  
10+ Never

guaranteed cost 1st time guaranteeing is worth it (in  )
7 6th  
8 7th  
9 8th  
10 9th  
11  
12+ Never

guaranteed cost 1st time guaranteeing is worth it (in  )
8 6th  
9 7th  
10 8th  
11 9th  
12  
13+ Never

guaranteed cost 1st time guaranteeing is worth it (in  )
9 6th  
10 6th  
11 8th  
12 9th  
13 9th  
14  
15+ Never

guaranteed cost 1st time guaranteeing is worth it (in  )
10 6th  
11 6th  
12 7th  
13 9th  
14 9th  
15  
16  
17+ Never

guaranteed cost 1st time guaranteeing is worth it (in  )
11 6th  
12 6th  
13 7th  
14 8th  
15 9th  
16 9th  
17  
18+ Never

guaranteed cost 1st time guaranteeing is worth it (in  )
12 6th  
13 6th  
14 7th  
15 8th  
16 9th  
17 9th  
18  
19  
20+ Never

guaranteed cost 1st time guaranteeing is worth it (in  )
13 6th  
14 6th  
15 7th  
16 8th  
17 9th  
18 9th  
19 9th  
20  
21+ Never

guaranteed cost 1st time guaranteeing is worth it (in  )
14 6th  
15 6th  
16 7th  
17 7th  
18 8th  
19 9th  
20 9th  
21  
22  
23+ Never

guaranteed cost 1st time guaranteeing is worth it (in  )
15 6th  
16 6th  
17 7th  
18 7th  
19 8th  
20 9th  
21 9th  
22 9th  
23  
24  
25+ Never

There is only one equipment with a base brut screw cost above 15 (the SK Radar), and as every equipment consuming expensive "Akashi exclusive" or rare equipment, the average screw cost is less important that the raw cost, meaning that guaranteeing the upgrade is always worth it

Improvement Guide

Several rankings for equipment improvements. Do note that:

  • Equipments to upgrade/improve are ranked from most advisable at 1, to least advisable at 10.
  • Many equipment possibly improbable are omitted, as they are either:
    • Already listed in one of the lists,
    • Are obtainable elsewhere for cheaper,
    • Are just not worth improving or upgrading.
  • Some equipment can be in several lists.

Quests Improvements

Several Quests require specific equipment to be upgraded in order to be completed, while others simply allow the use of upgraded equipment for conversion.

Quests Requirements

Here is the list of equipment that required to be improved to complete some quests:

  • All improvements are lost during conversions.
Quests Requirements
Quest Equipment   Level Notes
F36 61cm Triple (Oxygen) Torpedo Mount
61cm Quintuple (Oxygen) Torpedo Mount
  Both
F51 Type 2 Seaplane Fighter Kai  
F52 Type 2 Seaplane Fighter Kai  
F58 Zuiun (634 Air Group)  
F61 F61  
F63 F6F-5  
F74 Prototype 41cm Triple Gun Mount  
F76 12.7cm Twin Gun Mount Model A Kai 2  
F78 12.7cm Twin Gun Mount Model B Kai 2  
F87 Zuiun Kai Ni (634 Air Group)  
F101 Type 0 Reconnaissance Seaplane Model 11B  
F103 Type 3 Active Sonar  
F104 Daihatsu Landing Craft (Type 89 Medium Tank & Landing Force)  
F105 Type 1 Land-based Attack Aircraft Model 22A   Requires to craft 8 Tenzan Model 12A
F111 Type 98 Reconnaissance Seaplane (Night Recon)
Type 0 Reconnaissance Seaplane Model 11B
  Both
F116 35.6cm Twin Gun Mount Kai San (Dazzle Camouflage)  +3 All   past 3 are lost on conversion
F117 Late Model Bow Torpedo Mount (6 tubes)  
Fq1 Type 96 Fighter  
Fq7 12.7cm Twin Gun Mount Model A Kai 2  
Fy2 Swordfish  
Fy10 Type 0 Reconnaissance Seaplane  

Ultra Highly Advised

It is highly recommended to improve the following equipment to   before proceeding with those quests as any   are carried over to the reward , and the rewards cannot be improved afterward!

Ultra Highly Advised
Quest Equipment
F13 Type 97 Torpedo Bomber (Tomonaga Squadron)
F14 Type 99 Dive Bomber (Egusa Squadron)
F15 Zero Fighter Model 52C (601 Air Group)

Highly Advised

In those quests, any   the equipment has, are carried over to the reward. It is therefore advised to upgrade the equipment before completing the quest, as it is cheaper to do so.

Highly Advised
Quest Equipment Notes
F19 Type 97 Torpedo Bomber (Murata Squadron) Not improvable yet
F24 Type 0 Fighter Model 21 (Skilled) It is advised to start improvements with Fm1 for this chain.
F26 Type 0 Fighter Model 52 (Skilled)
F27 Zero Fighter Model 52C (w/ Iwai Flight)
F28 Type 0 Fighter Model 21 (Skilled) It is advised to start improvements with Fm1 for this chain.
F29 Zero Fighter Model 21 (w/ Iwamoto Flight)
F30 Zero Fighter Model 52A (w/ Iwamoto Flight)
Fm1 Type 0 Fighter Model 21
Fm2 Type 0 Fighter Model 21 (Skilled) It is advised to start improvements with Fm1.

Traps

Some quests allow the use of upgraded equipment for completion, but will not keep any of the current equipment improvements, and so should be cleared with unimproved equipment:

Traps
Quest Equipment
F40 Type 1 Land-based Attack Aircraft
F62 TBF
F86 Suisei Model 12A
F89 7.7mm Machine Gun
F107 Ki-102 B
F112 5inch Single Gun Mount Mk.30
F115 Smoke Generator (Smoke Screen)
Fq2 Type 96 Land-based Attack Aircraft
Fq5 Type 0 Fighter Model 52

Collection Improvements

Some equipment are only obtainable via Akashi upgrades.

  • The list can be found here
  • If completing the Kancodex is a personal goal, then crafting those equipment becomes a necessity in the long run.
  • Making all those equipment should NOT be a priority over the rest, as most are not very useful or even useless.
  • See below for when making those equipment overlap with advised improvements.

Upgrade Advice

Here is a list of improvements that have as a main goal to "upgrade" said equipment into a better one.

  • Do that certain upgrades can be done in chains, with part of the chain ranging from worse than the upgrade, equivalent to, or even better.
  • The "Total Srew Cost" is given as an indication, but does not reflect "real" with guaranteeing savings and consumed equipment being great factors to take into account.
  • Several good equipment are not listed there as they can be obtained otherwise more cheaply, or because the upgrade is just not worth it.
Upgrade Advice
Priority Level Equipment Goal Equipment To Upgrade Total Srew Cost Further Improvable? Notes
6 41cm Triple Gun Mount Kai Prototype 41cm Triple Gun Mount 69 Yes A good gun for BB(V)
5 41cm Twin Gun Mount Kai 2 41cm Triple Gun Mount Kai 92 Yes A good gun for BB(V), especially IJN ones
4 41cm Triple Gun Mount Kai 2 41cm Triple Gun Mount Kai 93 Yes A good gun for BB(V), especially IJN ones
2 12cm 30 Tube Rocket Launcher Kai 2 12cm 30-tube Rocket Launcher 40 Yes Needed to trigger the "AARB" that negate some plane damages
  • A goal is to 6, enough to equip a full "carrier fleet".
1 Type 2 Seaplane Fighter Kai Type 0 Reconnaissance Seaplane 40 Yes Great to maintain airpower without carriers
  • The goal is to have at least 6 good SPF
1 Kyoufuu Kai Type 2 Seaplane Fighter Kai 77 Yes Great to maintain airpower without carriers
  • The goal is to have at least 6 good SPF
3 Type 1 Armor Piercing Shell Type 91 Armor Piercing Shell 22 Yes Good AP shell, cheap to make
10 Type 1 Armor Piercing Shell Kai Type 1 Armor Piercing Shell 35 Yes The best AP shell, but extremely expensive
1 Special Type 2 Amphibious Tank Daihatsu Landing Craft (Type 89 Medium Tank & Landing Force) 39 Yes Geat against Installations
1 Daihatsu Landing Craft (Type 89 Medium Tank & Landing Force) Daihatsu Landing Craft 24 Yes Geat against Installations
4 Toku Daihatsu Landing Craft Daihatsu Landing Craft 29 Yes Good for Expeditions
5 Armed Daihatsu Daihatsu Landing Craft 23 Yes Geat against Installations and PT Imps
5 F6F-5 F6F-3 70 Yes +10 airpower fighter
7 Type 0 Fighter Model 64 (Skilled Fighter-bomber) Type 0 Fighter Model 64 (Air Superiority Fighter Specification) 70 Yes Good fighter-bomber with AAR
5 Shiden Kai 4 Shiden Kai 2 59 Yes +10 airpower fighter
8 Seafire Mk.III Kai Spitfire Mk.V 49 No Good fighter, with bonuses in some "European Events"
3 Spitfire Mk.V Spitfire Mk.I 33 Yes Great interceptor, further improbable, with bonuses in some "European Events"
6 Re.2005 Kai Re.2001 CB Kai 60 No +11 airpower fighter, with bonuses in some "European Events"
10 Re.2001 CB Kai Re.2001 OR Kai 49 Yes Only used to make the Re.2005 Kai
10 Fulmar (Reconnaissance Fighter/Skilled) Fulmar 39 No Only useful in some "European Events"
9 Type 99 Dive Bomber Model 22 (Skilled) Type 99 Dive Bomber Model 22 36 Yes Anti-Installation dive-bomber
6 SB2C-3 SBD-5 43 No Anti-Installation dive-bomber, with bonuses in some "European Events"
8 Prototype Type 97 Torpedo Bomber Kai (Skilled) No. 3 Model E (w/ Type 6 Airborne Radar Kai) Type 97 Torpedo Bomber (Skilled) 45 No A good night bomber
10 Tenzan Model 12A Tenzan 34 Yes Ok torpedo bomber, mostly used to improve the Type 1 Land-based Attack Aircraft Model 22A
9 Tenzan Model 12A Kai (w/ Type 6 Airborne Radar Kai) Prototype Type 97 Torpedo Bomber Kai No. 3 Model E (w/ Type 6 Airborne Radar Kai) 63 No Best craftable night bomber
5 Jet Keiun Kai Prototype Keiun (Carrier-based Reconnaissance Model) 86 No A Jet, coming with unique behaviors and great stats
8 Type 2 Two-seat Fighter Toryuu Model C Type 2 Two-seat Fighter Toryuu 33 Yes OK interceptor
3 Ki-96 Type 2 Two-seat Fighter Toryuu Model C 38 Yes Best craftable interceptor
8 Ki-102 B Ki-96 60 No Good LBB stat-wise, but with low range
5 Type 1 Fighter Hayabusa Model II Type 1 Fighter Hayabusa Model II 39 Yes Good interceptor
6 Shiden Kai (343 Air Group) 301st Fighter Squadron Shiden Model 21 Shiden Kai 71 No Great interceptor
7 Do 217 E-5 + Hs293 Initial Model Do 17 Z-2 63 No A great LBB with AAR but with low range, with bonuses in some "European Events"
10 Type 1 Land-based Attack Aircraft Model 34 Type 1 Land-based Attack Aircraft Model 22A 56 Yes Best craftable LBB, but is the most expensive equipment in the game:
7 Type 4 Heavy Bomber Hiryuu (Skilled) Type 4 Heavy Bomber Hiryuu 72 No A great LBB with AAR but with low range
10 12cm Single Gun Mount Kai 2 12cm Single Gun Mount 19 Yes A good very niche small gun
9 Prototype Long-barrel 12.7cm Twin Gun Mount Model A Kai 4 12.7cm Twin Gun Mount Model A Kai 2 38 Yes A great very niche small gun
3 5inch Single Gun Mount Mk.30 Kai + GFCS Mk.37 5inch Single Gun Mount Mk.30 Kai 101 No Best AACI small gun
9 12.7cm Twin Gun Mount Model C Kai 3 12.7cm Twin Gun Mount Model C Kai 2 34 Yes A good small gun, with great bonuses on some IJN ships
5 14cm Twin Gun Mount Kai 14cm Twin Gun Mount 17 Yes Great medium gun on some IJN ships,
  • Rarely more than 4 are needed
3 15.2cm Twin Gun Mount Kai 2 15.2cm Twin Gun Mount Kai 44 Yes Best CL gun
3 15.2cm Twin Gun Mount Kai 15.2cm Twin Gun Mount 36 Yes Best CL gun
9 15.5cm Triple Gun Mount Kai 15.5cm Triple Gun Mount 34 Yes Good CL gun
8 15.5cm Triple Secondary Gun Mount Kai 15.5cm Triple Secondary Gun Mount 34 Yes Good surface secondary gun
5 15.5cm Triple Secondary Gun Mount Kai 2 15.5cm Triple Secondary Gun Mount Kai 53 No Best surface secondary gun
10 8inch Triple Gun Mount Mk.9 mod.2 8inch Triple Gun Mount Mk.9 42 Yes Best cruiser gun for FP
7 35.6cm Triple Gun Mount Kai (Dazzle Camouflage) 35.6cm Twin Gun Mount (Dazzle Camouflage) 43 Yes Great gun for FBB
6 35.6cm Twin Gun Mount Kai 3 (Dazzle Camouflage) 35.6cm Triple Gun Mount Kai (Dazzle Camouflage) 70 Yes Great gun for FBB
9 16inch Mk.VIII Twin Gun Mount Kai 16inch Mk.V Twin Gun Mount 56 Yes Good gun for BB(V)
10 38.1cm Mk.I/N Twin Gun Mount Kai 38.1cm Mk.I Twin Gun Mount 48 Yes Good gun for FBB
9 16inch Mk.I Triple Gun Mount Kai + FCR Type 284 16inch Mk.I Triple Gun Mount + AFCT Kai 68 Yes Good gun for BB(V)
7 46cm Triple Gun Mount Kai 46cm Triple Gun Mount 69 Yes Very niche, best gun for the Yamato-class
10 51cm Twin Gun Mount Prototype 51cm Twin Gun Mount 85 Yes Very niche, has great FP
3 16inch Triple Gun Mount Mk.7 + GFCS 16inch Triple Gun Mount Mk.7 100 Yes Great gun for (F)BB(V) with high Acc
8 8cm High-angle Gun Kai + Additional Machine Guns 8cm High-angle Gun 49 Yes For RE usage only
5 Type C Kouhyouteki Type A Kouhyouteki 28 No A better Minisub
5 Type 13 Air Radar Kai (Late Model) Type 13 Air Radar Kai 55 Yes A dual-purpose radar, with good bonuses and usable in the RE of some IJN ships
6 15m Duplex Rangefinder Kai + Type 21 Radar Kai 2 + Skilled Fire Direction Center 15m Duplex Rangefinder + Type 21 Radar Kai 2 80 Yes A dual-purpose radar, great for (F)BB(V), especially the Yamato-class
10 SK + SG Radar SK Radar 94 Yes A dual-purpose radar, with only LoS as a great stat
9 Type 32 Surface Radar Kai Type 32 Surface Radar 58 Yes Best large surface radar
6 Type 4 Passive Sonar Type 93 Passive Sonar 29 Yes Good sonar at +12 ASW
5 Type144/147 ASDIC Type124 ASDIC 57 No Good sonar at +13 ASW
10 Type 3 Shell Kai Type 3 Shell 60 Yes Only marginal stat boost
7 Bi Type 40mm Twin Autocannon Mount QF 2-pounder Octuple Pom-pom Gun Mount 19 Yes Great AA gun, very cheap
6 Zuiun Model 12 (634 Air Group) Zuiun Model 12 69 Yes Good SPB, further upgradable and consumed to improve later variants
4 Zuiun (634 Air Group/Skilled) Zuiun Model 12 (634 Air Group) 56 Yes Great SPB, further upgradeable
3 Zuiun Kai 2 (634 Air Group) Zuiun (634 Air Group/Skilled) 86 Yes Great SPB, further upgradeable
1 Prototype Night Zuiun (Attack Equipment) Zuiun Kai 2 (634 Air Group) 110 Yes Best SPB, with a special Night Cut-In
10 S-51J Kai S-51J 96 Yes Best ASW, but extremely niche
6 Type 4 20cm Anti-ground Rocket Launcher (Concentrated Deployment) Shipborne Model Type 4 20cm Anti-ground Rocket Launcher 53 No Good for Anti-Installation only
4 Ryuusei Kai (Skilled) Ryuusei Kai 47 Yes Great torpedo bomber with AAR

Improvement Advice

Here is a list of improvements that have as a main goal to "enhance" said equipment's stats.

  • In some cases, the equipment can be upgraded, but the upgrade is inferior to the improved base equipment,
  • In some cases, the improved equipment only shows its best potential on certain ships, thanks to Visible Fit Bonuses,
  • Some of the listed equipment below are obtained from above listed upgrades,
  • Equipment being improved only for upgrade purposes are not listed there,
  • The improvements related to Quests are not listed there, and should be done with the quests in mind.
Improvement Advice
Priority Level Equipment Base Screw Cost Notes
1 Combat Ration 0 Only used to farm screws with Fd6
1 Shiden Kai 4 4 +12 airpower fighter
3 F6F-5 6 +12 airpower fighter
7 Type 0 Fighter Model 64 (Air Superiority Fighter Specification) 5 +11 airpower fighter
5 Type 0 Fighter Model 64 (Skilled Fighter-bomber) 6 Good fighter-bomber with AAR
10 Type 0 Fighter Model 64 (Two-seat w/ KMX) 5 Very niche fighter-bomber with ASW
9 Type 99 Dive Bomber Model 22 (Skilled) 3 Anti-Installation dive-bomber
10 Swordfish Mk.II (Skilled) 3 Torpedo bomber with bonuses in some "European Events"
9 TBF 3 Torpedo bomber with bonuses in some "European Events"
10 Type 2 Reconnaissance Aircraft 3 Ultra niche role as a Range extender
3 Ki-96 4 Great interceptor
5 Type 1 Fighter Hayabusa Model III A 4 Good interceptor
2 Spitfire Mk.V 3 Great interceptor, with bonuses in some "European Events"
8 Bomb-carrying Type 1 Fighter Hayabusa Model III Kai (65th Squadron) 4 Best LBB against DD only
4 Type 1 Land-based Attack Aircraft Model 34 5 Great LBB
9 Type 1 Land-based Attack Aircraft (Hachiman Force) 3 Good LBB, cheap
5 Type 1 Land-based Attack Aircraft (Nonaka Squadron) 5 Great LBB with AAR
10 12cm Single Gun Mount Kai 2 2 A good very niche small gun, cheap
8 12.7cm Twin Gun Mount Model A Kai 2 2 A good small gun, further upgradable, cheap
5 Prototype Long-barrel 12.7cm Twin Gun Mount Model A Kai 4 3 A great very niche small gun
4 12.7cm Twin Gun Mount Model A Kai 3 (Wartime Modification) + Anti-Aircraft Fire Director 4 A great niche small gun for AACI
9 12.7cm Single High-angle Gun Mount (Late Model) 2 Only one, very niche
6 12.7cm Twin Gun Mount Model C Kai 2 2 A good small gun, with great bonuses on some IJN ships
3 12.7cm Twin Gun Mount Model C Kai 3 5 A good small gun, with great bonuses on some IJN ships
1 12.7cm Twin Gun Mount Model D Kai 2 5 Best DD gun, with special bonuses for Night Cut-Ins
9 130mm B-13 Twin Gun Mount 5 A good very niche small gun
6 5inch Single Gun Mount Mk.30 Kai 7 A good small gun for AACI, further upgradeable
3 12.7cm Twin Gun Mount Model B Kai 4 (Wartime Modification) + Anti-Aircraft Fire Director 6 A great niche small gun for AACI
1 10cm Twin High-angle Gun Mount + Anti-Aircraft Fire Director 3 2nd best AACI small gun
4 14cm Twin Gun Mount Kai 3 Great medium gun on some IJN ships
6 Bofors 15.2cm Twin Gun Mount Model 1930 3 Good CL gun
5 15.2cm Twin Gun Mount Kai 2 Great CL gun
1 15.2cm Twin Gun Mount Kai 2 3 Best CL gun
8 15.5cm Triple Gun Mount Kai 4 Good CL gun
2 20.3cm (No.2) Twin Gun Mount 2 Great CA gun
1 20.3cm (No.3) Twin Gun Mount 2 Best CA(V) gun
6 8inch Triple Gun Mount Mk.9 2 2nd best cruiser gun for FP
4 8inch Triple Gun Mount Mk.9 mod.2 3 Best cruiser gun for FP
7 16inch Triple Gun Mount Mk.6 mod.2 4 Good gun for BB(V)
4 16inch Triple Gun Mount Mk.7 + GFCS 8 Great gun for (F)BB(V) with high Acc
9 16inch Mk.VIII Twin Gun Mount Kai 5 Good gun for BB(V)
8 16inch Mk.I Triple Gun Mount Kai + FCR Type 284 5 Good gun for BB(V)
10 30.5cm Triple Gun Mount Kai 4 Good gun for Gangut
9 38.1cm Mk.I/N Twin Gun Mount Kai 3 Good gun for FBB
10 38cm Twin Gun Mount Kai 3 OK gun for FBB
4 35.6cm Triple Gun Mount Kai (Dazzle Camouflage) 4 Great gun for FBB
4 35.6cm Twin Gun Mount Kai 3 (Dazzle Camouflage) 6 Great gun for FBB
2 38cm Quadruple Gun Mount Kai 7 Great gun for all (F)BB(V)
3 41cm Triple Gun Mount Kai 2 7 Great gun for IJN BB(V)
3 41cm Triple Gun Mount Kai 2 7 Great gun for IJN BB(V)
5 46cm Triple Gun Mount Kai 7 Very niche, best gun for the Yamato-class
8 51cm Twin Gun Mount 7 Very niche, has great FP
4 8cm High-angle Gun Kai + Additional Machine Guns 4 For RE usage only
8 90mm Single High-angle Gun Mount 1 Good for AACI, very cheap
9 10cm Twin High-angle Gun Mount Kai + Additional Machine Guns 4 For RE usage only
5 10cm Twin High-angle Gun Mount Battery Concentrated Deployment 5 Best secondary gun for AACI
8 15.2cm Triple Gun Mount 6 OK secondary
5 15.5cm Triple Secondary Gun Mount Kai 4 Good secondary
2 OTO 152mm Triple Rapid Fire Gun Mount 2 2nd best secondary
7 53cm Twin Torpedo Mount 1 Only one, very niche, cheap
5 533mm Quintuple Torpedo Mount (Initial Model) 3 Only good for USN ships
4 61cm Triple (Oxygen) Torpedo Mount Late Model 3 Best torpedo for some ships
3 61cm Quadruple (Oxygen) Torpedo Mount 1 Only one, very cheap
1 61cm Quadruple (Oxygen) Torpedo Mount Late Model 3 Best torpedo
2 61cm Quintuple (Oxygen) Torpedo Mount 3 Great torpedo for most ships
2 61cm Quintuple (Oxygen) Torpedo Mount 5 Great torpedo for most ships
7 Type 13 Air Radar Kai (Late Model) 3 A dual-purpose radar, with good bonuses and usable in the RE of some IJN ships
8 SG Radar (Initial Model) 6 Best small dual-purpose radar, should become upgradable, very expensive
8 Type 21 Air Radar Kai 2 5 Great dual-purpose radar for some ships
10 SK + SG Radar 6 A dual-purpose radar, with only LoS as a great stat
6 Type 32 Surface Radar Kai 5 Best large surface radar
5 Type 3 Active Sonar 2 Good for ASW, cheap
3 Type 3 Active Sonar Kai 4 Good for ASW
3 Type 4 Passive Sonar 3 Good for ASW, cheap
10 Type 0 Passive Sonar 3 Unusable on most ASW ships
3 Type 2 Depth Charge 2 Good for ASW, with AP, cheap
3 Type 3 Depth Charge Projector 2 Good for ASW, cheap
4 Type 3 Depth Charge Projector (Concentrated Deployment) 3 Good for ASW
3 Type 2 Depth Charge Kai 2 3 Good for ASW, with AP
2 Type 91 Armor Piercing Shell 1 Stat bonuses, further upgradeable
1 Type 1 Armor Piercing Shell 1 Stat bonuses, further upgradeable
10 Type 1 Armor Piercing Shell Kai 7 Stat bonuses
1 Type 3 Shell 4 Gives marginal stat bonuses, further upgradeable
2 Type 3 Shell Kai 6 Gives some fit bonuses with improvement
4 Type 3 Shell Kai 2 6 Gives many fit bonuses with improvement
4 2cm Flakvierling 38 3 Has great fit bonuses
1 12cm 30-tube Rocket Launcher Kai 2 4 Most useful AA gun, used for the AARB
5 25mm Triple Autocannon Mount (Concentrated Deployment) 3 Good AA gun for AACI
2 Type 94 Anti-Aircraft Fire Director 2 Great to provide Acc via RE on most ships, also used for some AACI
10 New Model High Temperature High Pressure Boiler 8 Good at +7 only, to gain Speed bonuses, but cheaper elsewhere
5 New Kanhon Design Anti-torpedo Bulge (Medium) 6 Good to provide armor
10 Pugliese Underwater Protection Bulkhead 4 Can provide armor on some Italian ships
5 New Kanhon Design Anti-torpedo Bulge (Large) 6 Good to provide armor
2 Searchlight 2 Only one, for some Night Battle cases
10 Type 96 150cm Searchlight 3 Only one, mostly inferior to the base one
10 Swordfish Mk.II Kai (Reconnaissance Seaplane Model) 3 Good on some European ships
3 Type 0 Observation Seaplane 2 Good on most ships
3 Type 0 Reconnaissance Seaplane Model 11B 4 Great recon for all ships
9 Fairey Seafox Kai 4 Good on some European ships
3 Shiun 4 Best LoS recon
5 Ro.44 Seaplane Fighter bis 4 good to maintain airpower without carriers
2 Type 2 Seaplane Fighter Kai (Skilled) 7 Great to maintain airpower without carriers
2 Kyoufuu Kai 4 Great to maintain airpower without carriers
2 Kyoufuu Kai 2 7 Great to maintain airpower without carriers, best SPF
10 Laté 298B 3 Niche French SPB
5 Zuiun (634 Air Group/Skilled) 6 4th best SBP
3 Zuiun Kai 2 (634 Air Group) 8 2nd best SBP
10 S-51J Kai 8 Best ASW, but extremely niche
11 Type 3 Command Liaison Aircraft Kai 3 Good ASW, but almost useless
1 Daihatsu Landing Craft (Type 89 Medium Tank & Landing Force) 2 Best against Installations
1 Special Type 2 Amphibious Tank 2 Best against Installations
6 Toku Daihatsu Landing Craft 2 Good for Expeditions
3 Soukoutei (Armored Boat Class) 2 Geat against Installations and PT Imps
3 Armed Daihatsu 3 Geat against Installations and PT Imps
5 Skilled Deck Personnel + Aviation Maintenance Hands 2 For CV(B/L) RE usage only

Improvement Traps

Here is a list of equipment that should NOT be upgraded, as they are needed to upgrade better equipment, and thus upgrading them renders them less valuable.

Improvement Traps
Equipment
Prototype 35.6cm Triple Gun Mount
Prototype 46cm Twin Gun Mount
Type 22 Surface Radar Kai 4
Type 21 Air Radar Kai
Zuiun Model 12 (634 Air Group)
Tenzan Model 12A

See Also