The Royal Cannon sinks passing ships foolish enough to sail too close to your haven. These wrecks provide your salvage crews enough scavenged Gold and Lumber to increase your total production by 5% with each level upgrade. The Cannon will be destroyed by enemy attacks if left undefended. It can be repaired to Level 1 in one minute, and requires no Resources or Rubies to upgrade.
You may build only one Royal Cannon.
To build the Royal Cannon do the following:
1. Go to your Haven.
2. Click 'Construction'
3. Open the 'Resource' buildings tab and select the Royal Cannon.
4. Choose a place inside your Haven and begin construction.