How to do a naval invasion against heavily defended ports

[SophieX]

As in absolute sense lower negative modifier (penalty) for fighting invasion battles.

Even with pure marines you only reduce the penalty for invasions from -70% to -20%. You won't get rid of it.

Ok, that was my understanding too.

 

[Mister Analyst]

So it seems, the "only" advantages real marines have as "invaders", is 50% more attack. Is this correct ?

Not quite. Special Forces (marines, mountaineers, paratroopers) have higher organization. The table below has been verified by in-game testing and also confirmed by HOI4 wiki page Land units.

UNIT TYPE	ORGANIZATION
Infantry	60
Marines	70
Mountaineers	70
Paratroopers	70

 

[kettyo]

I don't remember ever having problems with org, if I invaded the Japanese Home Islands, starting from Hawaii as USA.

Good to know, thanks!