How to Do a Naval Invasion in HOI4 (Step-by-Step)

In Hearts of Iron IV, a popular strategy game, naval invasions play a crucial role in expanding your territory and winning wars. However, for newcomers, naval invasions can be a bit challenging.

In this tutorial, we will cover the basics of naval invasions, including how to research, plan, and execute them effectively.

Researching Naval Transports

Researching Naval Transports
Researching Naval Transports

To start with naval invasions, you need to research naval transports under your naval tab. You must research the first transport ships to enable you to invade up to ten troops at a time around your entire country. Although this can seem restrictive, knowing how to use those ten troops can help you win naval battles.

Marines and Amphibious Attacks

Marines play a crucial role in naval invasions since they provide a 50% bonus for amphibious attacks on coastal regions. They are useful for attacking coastal regions such as ports and cities.

If you’re going to attack a place like Lomé, you’ll need Marines rather than foot infantry.

Establishing Naval Supremacy

Establishing Naval Supremacy
Establishing Naval Supremacy

The first and foremost requirement for a successful naval invasion is naval supremacy. You’ll need ships and convoys to escort your troops across the sea. You can select the areas to be convoyed by left-clicking the corresponding naval units.

Planning a Naval Invasion

Planning a Naval Invasion
Planning a Naval Invasion

To plan a naval invasion, select the two units you want to use, then click on your general in your battle plans. Select the naval invasion option and left-click the port you want to invade from. You can invade from your own port or an allied port, but not a neutral port.

Attacking Multiple Ports

You can distract your enemy by attacking multiple ports simultaneously. However, to do this, you’ll need to research the necessary tech to hold more units. You can hold up to 50 units with the next tech level, making it possible to attack multiple ports at once.

Related | 5 Best Methods to Speed Up Hearts of Iron IV

Establishing Supply Lines

To establish supply lines, you’ll need to capture a port. If you invade a coast and your troops are dying, it’s probably because you didn’t establish a supply chain.

Your troops won’t get supplies if there’s no port to deliver them to. Besides, you cannot ship any more troops without a naval invasion order if you don’t have a port.

Common Problems and Solutions

Some common problems you may encounter with naval invasions include troops not firing even with naval supremacy, troops not ready yet, and not having enough convoys.

To check if your troops are ready, hover over the arrow to see how many days you have left. Check the number of convoys you have to ensure you can deliver the troops.


Naval invasions can be tricky, but once you master the basics, they can become a powerful tool in your arsenal. With naval supremacy, proper planning, and research, you can establish supply chains, distract your enemy, and capture ports to expand your territory.

If you encounter any problems, remember to check your troops’ readiness and the number of convoys available.


  • Matthew Flores

    Matthew Flores plays games for a living... what a life! He began with World of Warcraft when he was just a young man; nowadays, he has evolved to play every genre—grand strategies, RPGs, shooters, MMOs, and everything else! With this being his passion, he dreams of sharing his 1000s of hours of knowledge and expertise with others by creating YourGlobalGamer.

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