This upgrade can give the pure naval Imperial units (Yari Minisub, Sea-Wing, Naginata Cruiser, Shogun Battleship) 25% additional armor, 25% additional speed, and 25% additional vision. Affected units also have the flag of Empire painted prominently on them.
- The extra painting from the Fortified Fleet does not apply to vessels built before the upgrade in the original Red Alert 3. This was corrected in Red Alert 3: Uprising.
- Advanced aeronautics - Allied aircraft upgrade counterpart
- Grinder treads - Soviet grinder units upgrade counterpart