Ahoy! I really believe that it was a good move for the devs to make events expire after a certain amount of time, but 20 minutes is not enough in a game as big as this. There are multiple reasons why I feel it needs to be increased:

• It feels awful when you sail halfway across the map to have despawn when your close
• They cycle out so fast that they don't feel special anymore, making skull forts less desired
• The cloud animation for expiration and completion are the same, (we used to use it as an indicator that a crew has just completed the event).

My solutions:

• Add 10 more minutes to the expiration timer for both events (forts & fleets)
• Make the cloud animation for completion different (then the animation for event expiration)