Many underwater islands feature Black Smokers. These cease activity after up to 10 hours. When they're inactive, you can mine Iron, Copper, Gold or Uranium without using a deposit; and therefore without depleting resources. You can stop the activity of a Black Smoker by developing technologies in your Academy under "Fertilities and Resources". Note that this system has changed in the Deep Ocean expansion.
How do you name your islands?
Got nice ideas for future polls? Want to vote on older polls? Click here!