Barrels are storage containers for liquids, such as rum, and some dry goods, such as dried beef or dried fruit. In the game, barrels found around the various islands may be searched for needed quest objects.
In Pirates Online, a barrel is also a container used to carry additional cannonballs and increase the pirate's ammunition between visits to the gunsmith. They can be upgraded to hold more cannonballs:
|Small Barrel||500||Cannon 5|
|Medium Barrel||2000||Cannon 10|
|Large Barrel||8000||Cannon 17|