Submarine (Civ4)

The following units can be upgraded to Submarine:
* Caravel
** Carrack
== Strategy ==
Submarines are invisible to most units. They can explore rival territory and can carry special units, but are visible (vulnerable) to enemy Destroyers and other submarines, especially Attack Submarines, which gain a +50% strength bonus against regular Submarines.
Airships also have the ability to detect Submarines, but they lose this ability when upgraded to Fighters. Because Airships can no longer be produced after Flight is discovered, it may be advisable to keep some older Airships around, in order to detect enemy Submarines.
== Civilopedia entry ==
== See also ==
* Submarine in other games