User blog comment:C. Scar/Ship Customization - Plans/@comment-3476348-20111212004636/@comment-1140008-20111212005137

What you do is, you choose one of the Three Upgrade paths. (Reinforced, Cargo, and Streamlined) You then upgrade to rank I of one of those. Then to rank II, then to rank III, at rank IV, it changes from the path you chose. You can choose between 3 special broadside types to have. (these choices vary per what upgrade path you chose) Note that the skills you got with the normal hull upgrade will go away when you choose a special broadside. Also, not every shot fired out of your broadsides will be a special ammo. There will be a % chance that fury/explosive/thunder/etc will be fired out of your broadsides.