Evade Collision Attack: Control Tower + Special Rudder
Sea Mine Removal: Marine Sweeper + Casting Net
Bullet-proof Armouring: Set of Repair Tools + Metal Work
Intensive Charge: Admiral's Cabin + Munitions Chambers
Command Post: Control Tower + Admiral's Cabin
Watertight Bulkhead: Anti-skid Rope + Hull Bulkhead Plating
Direct Hit Prevention: Control Tower + Mast Top
Special Sterncastle: Stern Deck + Set of Dismantling Tools