Hearts of Iron IV Guide | Ship Templates: Best Submarine Designs

Submarines in Hearts of Iron IV basically have a single purpose. They are there to sink ships and not be seen, so specializing them in that aspect is very important. Having a long range with your submarines is also a good idea since you'll be focusing on enemy logistics convoys rather than warships. 

Designs are nothing without composition, though, so firstly, you should focus on having 20 flotillas in each fleet. Here are some of the best submarine designs for your navies.

Starter Submarine: 1936

So, your 1936 Submarine is your basic one; you don't really have many things researched yet. Sometimes, you'll not even have the 1936 Submarine researched. However, this is basically going to be your main submarine for a good chunk of the game. Eventually, you'll want to upgrade all modules to Tier 3 or Tier 4. Regardless, the design should be:

• Hull: 1936 Submarine Hull
• Torpedoes: Torpedo Tubes II
• Rear 1: Torpedo Tubes II
• Engine: Submarine Engine II

Minelayer Submarine: 1936

Self-explanatory, this is your submarine focusing on minelaying activities. Nothing more to it. They hinder enemy vessels and reduce naval supremacy. Keep Torpedos to Tier 1, but try and upgrade everything else to 3 or 4.

• Hull: 1936 Submarine Hull
• Torpedoes: Torpedo Tubes I
• Rear 1: Minelaying Tubes
• Engine: Submarine Engine II

Mid-Game Submarine: 1940

This is the submarine you'd usually get a bit after the war starts. You will find a few new and useful modules here, including Snorkel and Radar. Now, the Snorkel makes it harder for enemies to detect your subs, which is very invaluable. On the other hand, you can also equip it with Radar to make it more effective at detecting enemy fleets. At this stage, the Snorkel is slightly more effective than Radar.

• Hull: 1940 Submarine Hull
• Torpedoes: Torpedo Tubes III
• Front 1: Torpedo III
• Middle 1: Snorkel I
• Rear 1: Torpedo III
• Engine: Submarine Engine III

Late-Game Submarine: 1944

These are the super late-game submarines that you start dropping way later into your game. Some games might not even have these, as it's not really worth it to rush Submarines.

• Hull: 1944 Submarine Hull
• Torpedoes: Torpedo Tubes IV
• Front 1: Torpedo Tubes IV
• Middle 1: Snorkel II
• Rear 1: Torpedo Tubes IV
• Engine: Submarine Engine IV

Check out our Hearts of Iron IV: Götterdämmerung DLC review and other guides below:

• Hearts of Iron IV Divisions Guide
• Hearts of Iron IV Guide | Division Templates
• Hearts of Iron IV Guide | Console Commands for Modding
• Hearts of Iron IV Guide | Navy Tips and Tricks
• Hearts of Iron IV Guide | Naval Doctrines & Spirits