Submarine

Overview
The Submarine, also known as the Sub, is an original researchable naval unit from The Conquerors 3 added in the Naval Expansion Update. Known for being the only stealth-based naval unit in the game currently, it is considered one of the most annoying units to fight against, along with the Stealth Bomber and the Space Fighter, as the Submarine has the unique ability to cloak. Selecting a Submarine and pressing N will make it invisible to enemy players and units, allowing them to pass by undetected.

Additionally, they cannot be attacked by any units except for other Submarines, or Destroyers.

Submarines will self-destruct if they are the only remaining units on a team, since their cloaking ability inhibits them from being destroyed and causing a stalemate.

Usage
When using this, people usually focus on destroying the enemy fleet and/or naval ports to get naval dominance, they also usually rely on an ally to get an actual fleet made out of units like Battleships or Aircraft Carriers. Subs also have the fastest research speed out of all units, taking only 2 minutes to be completely done.

However, unlike all other naval units, the Submarine can only target other naval units and buildings close to the shore, making it useless for Naval/Air fights, although, as stated before, they can only be hit by Destroyers.

Strategy

 * A full fleet of destroyers can win against a full fleet of submarines, heavily damaged. This makes destroyers extremely useful even if your enemy has a full submarine fleet, don't forget that their allies may also have a good fleet, leading to your death.
 * Another strategy is to use Subs to escort Aircraft Carriers, or ACs, this can lead to its death because they can't distract the enemy ships, different from Destroyers, for example. If you're using them for this purpose, always remember to have a few Battleships or even Destroyers themselves to help the AC.
 * Use the Submarines to quickly gain naval supremacy and/or disable their naval economy of your enemies because most people don't know the counter to the unit, making them lose their naval shipyard and/or Oil Rigs.
 * Due to the low research time, submarines can be quickly researched and built by weaker teams to fight against stronger opposing teams with larger fleets. Just one to three submarines can effectively counter more expensive navies due to the fact that only destroyers and other submarines can damage them.

Trivia

 * The Submarine was only in The Conquerors 3.
 * Submarines do not show up on enemies minimap.
 * Only Destroyers can target Submarines when submerged.
 * It is the third fastest unit in the game, and the fastest unit produced by the Naval Shipyard.
 * It's price was reduced from $150 to $110 during the Naval Balance Update.
 * Players are able to see its health bar when damaged, even if its submerged.
 * Due to their annoying nature, there is a cooldown between submerging and ascending submarines.