Introduced with the Man the Guns DLC, the ship designer completely changed the game when it comes to managing your navy in Hearts of Iron IV. Along with the designer, patch 1.6 radically altered naval combat and added naval terrain to the game. There are an extensive amount of options when it comes to building your navy, so you might not have the ability to research every component. Prioritize which components are most important to you and temporarily downgrade some components until you get the requisite technology.
Note: If the game doesn’t let you produce some of the designs listed below, make sure you are not affected by the London Naval Treaty.
Due to submarines being nerfed in 1.12, spamming subs is no longer a viable option for fleet-building. They are really only useful for convoy-raiding and some niche fleet compositions.
Capital Ship Designs
Capital ships are the strongest ships and as such have the most expensive designs in Hearts of Iron IV. They’ll play an important role in any strike force group.
Carriers serve as mobile airbases that can be useful for projecting airpower on other continents or in the middle of the ocean. You will have to produce naval planes for them, normal ones won’t work for carriers.
The backbone of any strike force is the battleship. Battleships are by far the single strongest ship you can produce in Hearts of Iron IV.
Battlecruisers are slightly weaker than a battleship, but make up for it with increased speed. In the designs below, I avoid upgrading some components that would reduce the speed, but feel free to modify this to your liking.
Heavy Cruiser Designs
Compared to other capital ships, heavy cruisers aren’t worth producing in most scenarios. They lack the speed of battlecruisers and the raw power of battleships. You should only resort to heavy cruisers if you have both a weak economy and no other capital ships.
Screening Ship Designs
Although they aren’t as flashy as capital ships, screening ships play a vital role in naval combat in Hearts of Iron IV. Screening ships can be used to help protect capital ships or perform niche roles in combat like Anti-Air.
Destroyers are extremely flexible and cheap to produce. You will need to produce large quantities of destroyers for them to be effective in strike forces.
Light Cruiser Designs
Compared to destroyers, light cruisers are quite a bit stronger and more expensive. A combination of both screening ships will be best when building your strike forces.
Building a competent navy in Hearts of Iron IV requires well-designed ships. Remember that the naval designer allows plenty of customization, so feel free to modify the designs to fit your needs. These ship designs should help you master the seas and fulfill any objective, from raiding convoys to naval invasions.