When a DirectSail update (such as Land Ho or Sail Ho) occurs, that erases the ships from the previous DirectSail update.
The only way to prevent that from happening is by pressing the zero-key on your keyboard, which toggles DirectSail on/off.
This could be useful if one of the previous ships just surrendered and you want to capture her and not risk losing her to a DirectSail update.
I'm glad you like the Iron Man Mode and other realism options. While I never have the time to play like that, I do like the idea of getting much more involved in the game that way.
The only way to prevent that from happening is by pressing the zero-key on your keyboard, which toggles DirectSail on/off.
This could be useful if one of the previous ships just surrendered and you want to capture her and not risk losing her to a DirectSail update.
I'm glad you like the Iron Man Mode and other realism options. While I never have the time to play like that, I do like the idea of getting much more involved in the game that way.