Development

Ship-borne plane
(Higher chance if flagship is an aircraft carrier)

HQ level guideline is 20. For particularly rare equipment more than 30.

Machine gun, cannon, shell
(Higher chance if flagship is a battleship)

HQ level guideline is 20. For particularly rare equipment more than 30.

Sonar and depth charges
(Higher chance if flagship is a light cruiser or destroyer)

HQ level guideline is 10. For particularly rare equipment more than 20.

Radar
Radar improves accuracy, anti-air, and contributes to fleet-wide air superiority.

HQ level guideline is 20. For particularly rare equipment more than 30.

Note: Not easy to craft. New Admirals are advised to use Isuzu to get radars.

Engine/Turbine
Engines increase evasion.

(Higher chance if flagship is a submarine, aircraft carrier or battleship)

HQ level guideline is 20.