Oil Rig

Overview
For naval-based maps, Oil Spots are commonly used by players to gain income. With these Oil Spots, the user can place an Oil Ship to create an Oil Rig (This is done by pressing the letter "n" with an Oil ship selected over an Oil Spot). Oil Rigs work like Power Plants; Oil Rigs must be on top of an Oil Spot to be placed. To get an Oil Ship, a Naval Shipyard must have already been constructed. An Oil Ship costs $35 to make and gives the player $10 per minute meaning that they make a profit after 3 and a half minutes of operating time.

Usage
The main use of an Oil Rig is to gain extra income for the player. With maps that utilize Oil spots, a player can earn a maximum of  $80 and a minimum of $10 with oil rigs, depending on map type. What makes Oil Rigs valuable is that they are separated from the “beginner unit pool” e.g. Soldiers, Tanks, meaning that an enemy will have to create a gunboat of sorts to take them out. Being out of range from land units makes them safer for early game income, as not many players will target them at this time since only Boats, Planes, and Spaceships can reach them. Oil rigs themselves are quite durable, meaning that when an enemy is attacking with few troops you can counter them to save your Oil Rig before it is destroyed.

Strategies

 * With Oil Rigs being out of reach from different units, different strategies can be applied. One example is if you see an enemy training a naval fleet and you have an Oil Rig still standing, Water mines can be used to take out battleships and other sea units.
 * Oil rigs are a great income source as they are very cheap and produce the same amount of money as a Power Plant.

Trivia

 * Oil rigs have been in The Conquerors Mark II and The Conquerors 3.
 * Oil rigs are heavily used on the big naval maps because they are a cheap way of earning money.