While sailing the Sea of Thieves, you can spot various lights and clouds in the sky. Amongst them, you can find two different green tornados! Depending on where the tornado is, it can belong to the Legend of the Veil Voyage or the Ghost Fleet World Event.
No matter which of the encounters the swirling green funnel of doom is for, an epic naval battle primed with a giant pile of loot awaits you at the base of it!
Ghost Fleet World Event
If the green tornado is above an island, it is for the Ghost Fleet World Event.
When the Ghost Fleet World Event starts, a giant green tornado will appear over a haunted island. Previously, Captain Flameheart would oversee the World Event, but more critical endeavors have preoccupied his time since his resurrection. The Ghost Fleet World Event is a giant four-wave naval battle against Ghost Ships. To complete the World Event, you must destroy Flameheart’s flagship, the Burning Blade, during the final wave.

If you want to take out Flameheart’s Ghost Fleet yourself and need help, you can always check out our complete guide for the Ghost Fleet World Event here.
The Legend of the Veil Voyage
If the green tornado is on the outskirts of the map, above open water, and surrounded by three Ghost Garrison emplacements, it is for the Legend of the Veil Voyage.
A giant green tornado will appear during the third and final chapter of the Pirate Legend-exclusive voyage, the Legend of the Veil. The tornado is protecting a Haunted Fort. Once a crew has destroyed three surrounding Emplacements with cannonballs, the tornado will disappear and reveal the Haunted Fort. Inside the Haunted Fort is a pile of loot, including a Chest of Legends! Crews must destroy the fort to reveal the treasure.

If you are keen to do the voyage yourself and need a bit of help, you can always check out our complete guide for the Legend of the Veil here.
Whether you venture in to help the crew complete the voyage or sneak in to steal the loot for yourself, the green tornado means a grand adventure is on the horizon.